Glossary

Acceptable Use Policy (AUP)

A policy that communicates to users what specific uses of computer resources are permitted.

Access Control List (ACL)

A clearly defined list of permissions that specifies what actions an authenticated user may perform on a shared resource.

Access Point (AP)

A device designed to interconnct wireless network nodes with wired networks.

Accessible Rich Internet Applications (ARIA)

A specification by the World Wide Web Consortium (W3C) for adding semantics and other metadata to HTML to aid those who use assistive technology.

Active Directory (AD)

A product developed by Microsoft to manage users, computers and other devices on a network. It is provided as part of the Microsoft Windows Server operating system.

Address Resolution Protocol (ARP)

A TCP/IP protocol, used with the command line tool of the same name, to determine the MAC address that corresponds to a particular IP address.

Advanced Configuration Power Interface (ACPI)

Provides an open standard that operating systems can use to discover and configure computer hardware components, for example, to perform power management tasks such as, putting unused components to sleep, or, provide status monitoring. ACPI brings the power management under the control of the operating system, rather than it being BIOS centric, as with Advanced Power Management (APM).

Advanced Encryption Standard (AES)

An encryption standard created in the late 1990s, which utilises a symmetric block cipher, that uses a 128-bit block size and either a 128, 192 or 256-bit key size.

Advanced Host Controller Interface (AHCI)

An efficient way for motherboards to work with SATA host bus adapters. Using AHCI unlocks some of the advanced features of SATA, such as hot-swapping and native command queuing (NCQ)

Advanced Technology Attachment (ATA)

A series of hard drive standards defining both the older parallel ATA (PATA) and modern Serial ATA (SATA) drives.

Advanced Technology eXtended (ATX)

Popular motherboard form factor that generally replaced the AT form factor.

Alternating Current (AC)

Type of electricity in which the flow of electrons alternates direction, back and forth, in a circuit.

American Standard Code for Information Interchange (ASCII)

A character encoding that uses numeric codes in binary to represent characters. These include upper and lowercase English letters, numbers, and punctuation symbols.

Angled Physical Contact (APC)

Fibre-optic connector that makes physical contact between two fibre-optic cables. It specifies an 8-degree angle to the curved end, lowering signal loss. APC connectors have less connection degradation from multiple insertions compared to other connectors

Apple Filing Protocol (AFP)

A protocol developed by Apple for sharing files over a network. It was used in Apple's Macintosh operating systems up to macOS 10, however, it has mostly now been replaced by the standard Server Message Block (SMB) protocol.

Application Program Interface (API)

A library of related programme code available for programmers to use.

Application Service Provider (ASP)

A company that offers applications and services over the internet.

Asymmetric Digital Subscriber Line (ADSL)

A data communications technology that enables faster data transmission over copper telephone lines than a conventional voiceband modem can provide. Bandwidth and bit rate are said to be asymmetric because they are greater downstream to the customer, than upstream.

Asynchronous Transfer Mode (ATM)

A network technology that runs at speeds between 25 and 622 Mbps using fibre-optic cabling or Cat 5 or better UTP.

Authentication Header (AH)

Handles authentication and data integrity as part of IPsec.

Authentication, Authorisation, Accounting (AAA)

A security philosophy where a user trying to connect to a network must first present some form of credential to be authenticated and then must have limitable permissions within the network. The authenticating server should also record session information about the client.

Automatic Document Feeder (ADF)

A tray, usually on top of a scanner, or multifunction device, that holds a document and enables the device to grab and scan each page automatically for easier scanning, copying, or faxing of long documents.

Automatic Private Internet Protocol Addressing (APIPA)

A networking feature in operating systems that enables clients to self-configure an IP address and subnet mask automatically when a DHCP server isn’t available.

Blu-ray Disc (BD)

Optical disc format that stores up to 100 GB of data, designed as a replacement media for DVD.

Blu-ray Disc Recordable (BD-R)

A Blu-ray Disc that can be written to once.

Blu-ray Disc Rewritable (BD-RE)

A Blu-ray Disc that can be rewritten to several times.

Blue Screen of Death (BSOD)

Error screen that appears when Windows encounters an unrecoverable error.

Border Gateway Protocol (BGP)

An exterior gateway routing protocol that enables groups of routers to share routing information so that efficient, loop-free routes can be established. BGP connects Autonomous Systems on the Internet. The current version is BGP-4.

Botnet

A network of computers, or bots, as they are sometimes referred to, which are infected with malware and can be controlled remotely to, for example, carry out a distributed denial of service (DDoS) attack.

Bring Your Own Device (BYOD)

Mobile deployment model wherein users bring their own network-enabled devices to the work environment. These mobile phones, tablets, notebooks, and other mobile devices must be easily and securely integrated and released from corporate network environments using onboarding and offboarding technologies.

British Naval Connector/Bayonet Neill-Concelman (BNC)

A connector used with 10-BASE-2 coaxial cable. All BNC connectors must be locked into place by turning the connector clockwise 90 degrees.

Campus Area Network (CAN)

A network installed in a medium-sized space spanning multiple buildings.

Canonical Name (CNAME)

A DNS record that stores a fully qualified domain name. A common use is to provide an alias for another hostname.

Carrier-Sense Multiple Access with Collision Avoidance (CSMA/CA)

Access method used only on wireless networks. Before hosts transmit, they first listen for traffic. If the transmitting host does not hear any traffic, it will transmit its frame. It will then listen for an acknowledgement frame from the receiving host. If the transmitting host does not hear the acknowledgement, it will wait for a randomly determined period of time and try again.

Carrier-Sense Multiple Access with Collision Detection (CSMA/CD)

Obsolete access method that Ethernet systems used in LAN technologies, enabling frames of data to flow through the network and ultimately reach address locations. Hosts on CSMA/CD networks first listened to hear if there was any data on the wire. If there was none, the hosts sent out data. If a collision occurred, then both hosts waited a randomly determined period before retransmitting the data. Full-duplex Ethernet made CSMA/CD obsolete.

Cascading Style Sheet (CSS)

A language that is used to provide the look and feel to the structure of a web page, for example, the colour and font used for paragraph text.

Cathode Ray Tube (CRT)

Tube of a monitor in which rays of electrons are beamed onto a phosphorescent screen to produce images. Also, a shorthand way to describe a monitor that uses CRT rather than LCD technologies.

Central Processing Unit (CPU)

A microprocessor that acts as the brain of a computer, containing the circuitry necessary to interpret and execute program instructions such as arithmetic, logic, controlling and input/output operations.

Channel Service Unit (CSU)

A piece of equipment that connects a T-carrier leased line from the telephone company to a customer’s equipment, such as a router.

Ciphertext

Ciphertext is the result of plaintext being encrypted using an algorithm, known as a cipher.

Classless Inter-Domain Routing (CIDR)

The basis of allocating and routing classless IP addresses, not restricting subnet masks to /8, /16, or /24, which classful addressing did. Based on variable-length subnet masking (VLSM), where subnets can be allocated according to the needs of an organisation, such as /26 for a network with 254 or fewer nodes, or /30 for a network with only two nodes.

Coarse Wavelength Division Multiplexing (CWDM)

An optical multiplexing technology in which a few signals of different optical wavelength could be combined to travel a short distance.

Code Division Multiple Access (CDMA)

Early cellular telephone technology that used spread-spectrum transmission.

Command-Line Interface (CLI)

Allows a user to issue commands in the form of lines of text.

Common Vulnerabilities and Exposures (CVE)

A database hosted by the MITRE corporation, which incorporates a list of known vulnerabilities in publicly released software.

Communications and Networking Riser (CNR)

Proprietary slot used on some motherboards to provide a connection for modems, sound cards, and NICs that is free from sound interference.

Compact Disc (CD)

Optical disc format that stores up to 700MB of data or 80 minutes of music.

Compact Disc File System (CDFS)

A file structure, rules, and conventions used when organising and storing files and data on a CD. A generic name for ISO-9660.

Compact Disc Re-Writable (CD-RW)

A Compact Disc (CD) that can be rewritten to several times.

Compact Disc Read-Only Memory (CD-ROM)

A read only Compact Disc (CD).

Compact Disc Recordable (CD-R)

A Compact Disc (CD) that can be recorded to once.

Complementary Metal Oxide Semiconductor (CMOS)

Originally, computer systems had a standalone CMOS chip, which was a tiny bit of RAM hooked up to a small battery that enabled it to hold system settings for the BIOS firmware even with the computer turned off. This has long since been incorporated into the chipset. CMOS is often informally used to refer to the CMOS setup program or system setup utility.

Computer-Aided Design (CAD)

The use of computers to aid in the creation, modification, analysis, or optimisation of a design.

Confidentiality, Integrity, and Availability (CIA)

The CIA triad is widely considered to be the foundation of IT security. It is put into practice through various security methods and controls. Every security technique, practice, and mechanism put into place to protect systems and data relates in some fashion to ensuring confidentiality, integrity, and availability.

Content Addressable Memory (table) (CAM)

Content Addressable Memory (CAM) table is a system memory construct used by Ethernet switch logic which stores information such as MAC addresses available on physical ports with their associated VLAN Parameters. The CAM table, or content addressable memory table, is present in all switches for layer 2 switching. This allows switches to facilitate communications between connected stations at high speed and in full duplex regardless of how many devices are connected to the switch. Switches learn MAC addresses from the source address of Ethernet frames on the ports, such as Address Resolution Protocol (ARP) response packets.

Content Management System (CMS)

A web based application that allows non-technical users to manage the content of a website. These applications are built using web technologies such as PHP or the .NET Framework and utilise a database, for example, MySQL, PostgreSQL, Oracle or SQL Server, to store the website information.

Create, Read, Update and Delete (CRUD)

Refers to the possible ways to operate on stored data, such as in a database.

Cron

A tool used by a number of Linux distributions for automatically running tasks at a scheduled time.

Cyclic Redundancy Check (CRC)

A mathematical method used to check for errors in long streams of transmitted data with high accuracy. The CRC is found in the Frame Check Sequence (FCS).

Darknet

An area of the internet that cannot be indexed by search engines such as Google and are not normally accessible via a standard web browser, but instead through specialist software. A Darknet can be used for harmless means, such as for a corporate website, as well as illegal means, such as hacking and file sharing forums where users wish to stay anonymous.

Data Loss Prevention (DLP)

System or set of rules designed to stop leakage of sensitive information. Usually applied to Internet appliances to outgoing network traffic.

Data Service Unit (DSU)

A device used in digital transmission for connecting a CSU (Channel Service Unit) to Data Terminal Equipment (a terminal or computer), in the same way that a modem is used for connection to an analogue medium.

Database as a Service (DBaaS)

A cloud computing managed service offering that provides access to a database without requiring the setup of physical hardware, the installation of software or the need to configure the database.

Database Management System (DBMS)

Software designed to define, manipulate, retrieve and manage data in a database.

Decibel (dB)

A measurement of the quality of a signal.

Demilitarized Zone (DMZ)

A physical or logical subnetwork that contains and exposes an organisation’s external-facing services to an untrusted network, such as the Internet. Its purpose is to add an additional layer of security to an organisation’s local area network (LAN). The untrusted network can only access what is in the DMZ, whilst the rest of the network is secured behind a firewall. Also sometimes known as a perimeter network.

Denial-of-Service (DoS)

An attack that floods a networked resource with so many requests that it becomes overwhelmed and ceases functioning. DoS prevents users from gaining normal use of a resource.

Dense Wavelength Division Multiplexing (DWDM)

An optical multiplexing technology which a large number of optical signals of different optical wavelengths could be combined to travel over relatively long fibre cables.

Desktop as a Service (DaaS)

A cloud computing service that enables a user or organisation to virtualise user workstations and manage them as flexibly as other cloud resources.

Digital Subscriber Line (DSL)

A high-speed Internet connection technology that uses a regular telephone line for connectivity. DSL comes in several varieties, including asymmetric (ADSL) and symmetric (SDSL), and many speeds. Typical home-user DSL connections are ADSL with a download speed of up to 9 Mbps and an upload speed of up to 1 Kbps.

Digital Versatile Disc (DVD)

Optical disc format that provides for 4 – 17 GB of video or data storage.

Digital Versatile Disc Random Access Memory (DVD-RAM)

A rewritable disc endorsed by the DVD Forum. Using phase change technology, DVD-RAMs are like removeable hard disks, and the media can be rewritten 100,000 times, and have a capacity between 2.6GB and 9.4GB.

Digital Versatile Disc Recordable (DVD-R)

A DVD that can be written to once.

Digital Versatile Disc-Read Only Memory (DVD-ROM)

A read only DVD.

Digital Versatile Disk Rewritable (DVD-RW)

A DVD that can be rewritten to 1000 times.

Digital Video Interface (DVI)

Special video connector designed for digital-to-digital connections; most commonly seen on PC video cards and LCD monitors. Some versions also support analogue signals with a special adapter.

Direct Current (DC)

Type of electricity in which the flow of electrons is in a complete circle in one direction.

Direct Memory Access (DMA)

Technique that some PC hardware devices use to transfer data to and from the memory without using the CPU.

Discretionary Access Control (DAC)

Authorisation method based on the idea that there is an owner of a resource who may at his or her discretion assign access to that resource. DAC is considered much more flexible than mandatory access control (MAC).

Distributed Denial of Service (DDoS)

A multicomputer assault on a network resource that attempts, with sheer overwhelming quantity of requests, to prevent regular users from receiving services from the resource. Can also be used to crash systems. DDoS attacks are usually executed using botnets consisting of compromised systems referred to as zombies.

Distributed File System (DFS)

A set of client and server services that allow an organisation using Microsoft Windows servers to organise many distributed SMB file shares into a distributed file system. DFS has two components to its services, location, via the namespace component, and redundancy, via the file replication component. Together, these components improve data availability in the case of failure or heavy load by allowing shares in multiple different locations to be logically grouped together under one folder, the 'DFS root'.

Document Object Mode (DOM)

The DOM is an API, or interface, which is loaded in a web browser, that allows for interaction with HTML and XML documents. It represents these documents in a tree structure, where each node is an object representing a part of the document.

Domain Name System (DNS)

A TCP/IP name resolution system that resolves hostnames to IP addresses, IP addresses to hostname, and other bindings, like DNS servers and mail servers for a domain.

Double Data Rate (DDR)

A type of computer memory, which is an advanced version of SDRAM, that can transfer data twice as fast as regular SDRAM chips. This is because DDR memory can send and receive signals twice per clock cycle.

Double Data Rate 2 (DDR2)

An improved version of DDR memory that is faster and more efficient.

Double Data Rate 3 (DDR3)

A type of memory that is similar to DDR2 RAM, but uses roughly 30% less power and can transfer data twice as fast.

Double Data Rate 4 (DDR4)

A type of memory that has faster data transfer rates and larger capacities than DDR3. It can also operate at a lower voltage, making it more power efficient.

Doxing

The practice of researching and publishing private or identifiable information on the internet, regarding an individual or organisation.

Drive-by Download

A drive-by download is where something is downloaded from the internet to a computer without the prior knowledge of the user, or where a download is authorised by the user but the full consequences of the download are not understood.

Dual In-Line Memory Module (DIMM)

A 32 or 64-bit type of DRAM packaging with the distinction that each side of each tab inserted into the system performs a separate function. DIMMs come in a variety of sizes, with 184, 240 and 288 pins being the most common on desktop computers.

Dynamic Host Configuration Protocol (DHCP)

A protocol that enables a DHCP server to set TCP/IP settings automatically for a DHCP client.

Dynamic Link Library (DLL)

A type of file which contains a library of functions and other information that can be accessed by a Microsoft Windows based piece of software.

Dynamic Random Access Memory (DRAM)

Memory used to store data in most personal computers. DRAM stores each bit in a 'cell' composed of a transistor and a capacitor. Because the capacitor in a DRAM cell can only hold a charge for a few milliseconds, DRAM must be continually refreshed, or rewritten, to retain its data.

Effective Isotropic Radiated Power (EIRP)

The measured radiated power of an antenna in a specific direction.

Electromagnetic Interference (EMI)

Electrical interference from one device to another, resulting in poor performance of the device being interfered with.

Electromagnetic Pulse (EMP)

Potentially damaging burst of electromagnetic energy caused by events such as electrostatic discharge (ESD), lightning, nuclear detonations, and so on.

Electronic Industries Alliance (EIA)

Standards organisation specialising in the electrical and functional characteristics of interface equipment, which ceased operation in 2011.

Encapsulating Security Payload (ESP)

A member of the Internet Protocol Security (IPsec) set of protocols that encrypt and authenticate the packets of data between computers using a Virtual Private Network (VPN). The focus and layer on which ESP operates makes it possible for VPNs to function securely.

Encrypted File System (EFS)

A feature on Microsoft Windows introduced in version 3.0 of NTFS, that provides filesystem level encryption. This technology enables files to be transparently encrypted to protect confidential data from attackers with physical access to the computer. It is available on all versions of Windows, except the Home edition, from Windows 2000 onwards. By default, no files are encrypted, but encryption can be enabled by users on a per-file, directory or drive basis.

Encryption

The process of converting plain text into ciphertext to prevent unauthorised access.

Enhanced Interior Gateway Routing Protocvol (EIGRP)

Cisco’s proprietary hybrid protocol that has elements of both distance vector and link state routing.

Error Correction Code (ECC)

Special software, embedded on hard drives, that constantly scans the drives for bad blocks.

Extended Unique Identifier (EUI)

The term used by the IEEE to refer to the 48-bit MAC address assigned to a network interface, which is sometimes referred to as EUI-48. The first 24-bits of the EUI-48 are assigned by the IEEE as the organisationally unique identifier (OUI).

Extensible Application Markup Language (XAML)

A markup language developed by Microsoft, that is used for creating application interfaces.

Extensible Authentication Protocol (EAP)

Authentication wrapper that EAP-compliant applications can use to accept one of many types of authentication. While EAP is a general-purpose authentication wrapper, its only substantial use is in wireless networks.

Fibre Channel over Ethernet (FCoE)

A computer network technology that encapsulates Fibre Channel frames over Ethernet networks. This allows Fibre Channel to use 10 Gigabit Ethernet networks (or higher speeds) while preserving the Fibre Channel protocol.

File Allocation Table (FAT)

Hidden table that records how files on a hard disk are stored in distinct clusters; the only way DOS knows where to access files. The address of the first cluster of a file is stored in the directory file. The FAT entry for the first cluster is the address of the second cluster used to store that file. In the entry for the second cluster for that file is the address of the third cluster, and so on until the final cluster, which gets a special end of file marker. There are two FATs, mirror images of each other, in case one is destroyed or damaged.

File Transfer Protocol (FTP)

A protocol that works at the application layer, which is used to transfer files over a network connection. FTP utilises TCP ports 20 and 21.

File Transfer Protocol Secure (FTPS)

A protocol that works at the application layer, which is used to transfer files over a network connection, using FTP over an SSL or TLS connection.

Firewall

A network security system, which monitors traffic to and from a computer network. It has the ability to allow or block traffic depending on a set of predefined rules. Firewalls can be implemented using software, hardware or a combination of the two.

First Hop Redundancy Protocol (FHRP)

A method of ensuring high data availability by taking multiple routers and grouping them into a virtual router with a single virtual IP address that clients use as a default gateway. Common FHRP protocols are the open standard Virtual Router Redundancy Protocol (VRRP), Cisco’s proprietary Hot Standby Router Protocol (HSRP) and Gateway Load Balancing Protocol (GLBP).

First In, First Out (FIFO)

A method of processing and retrieving data. In a FIFO system, the first items entered are the first ones to be removed.

General Data Protection Regulations (GDPR)

European Union law that specifies a broad set of rights and protections for personal information of EU citizens.

Generic Routing Encapsulation (GRE)

A tunnelling protocol developed by Cisco Systems that can encapsulate a wide variety of network layer protocols inside virtual point-to-point links or point-to-multipoint links over an Internet Protocol network.

Gibabit Interface Converter (GBIC)

Modular port that supports a standardised, wide variety of gigabit interface modules.

Global System for Mobile Communication (GSM)

Early cellular telephone networking stardard that is now obsolete.

Globally Unique Identifier (GUID)

A 128-bit number used to uniquely identify information in computer systems.

Hardware Assisted Virtualisation (HAV)

A platform virtualisation approach that enables efficient full virtualisation using help from hardware capabilities, primarily from the host processors. Hardware assisted virtualisation was added to x86 processors (Intel VT-x and AMD-V) in 2005 and 2006 respectively.

Heating, Ventilation, and Air Conditioning (HVAC)

All the equipment involved in heating and cooling the environment within a facility. This includes boilers, furnaces, air conditioning units and ducts, plenums, and air passages.

High Availability (HA)

A collection of technologies and procedures that work together to keep an application available at all times.

High-Definition Multimedia Interface (HDMI)

A single multimedia connection that includes both high-definition audio and video. Used to connect computers, LCD displays, projectors and VR headsets, as well as various other devices in the home such as digital TV, DVD player, Blu-ray player, Xbox, Playstation and AppleTV with the television.

Honeypot

A computer system or portion of a network that has been set up purely for the purposes of attracting intruders. As there are no legitimate users in a system such as this, unauthorised activity is easy to spot.

Hub

An electronic device that sits at the centre of a star bus topology network, providing a common point for the connection of network devices. Hubs repeat all information it receives to all connected devices and have been replaced by switches.

Hyper-Text Markup Language (HTML)

A language that is used to provide the structure of web pages, using tags to define different parts of the page structure, for example, <h1> tags to denote the largest headings, or <p> tags for paragraphs of text.

Hyper-Text Transfer Protocol (HTTP)

A network protocol that facilitates the transfer of documents, such as web pages, on the web, typically between a web browser and a server.

Hypertext Transfer Protocol Secure (HTTPS)

A secure version of HTTP in which hypertext is encrypted by Transport Layer Security (TLS) before being sent over the network. Prior to TLS, this was accomplished using Secure Sockets Layer (SSL).

Immutable Object

A computer programming term used to describe an object whose state cannot be changed after it has been defined.

Industrial Control System (ICS)

System that monitors and controls machines such as those in a factory or chemical plant, or even just a large HVAC system in an office building.

Infrastructure as a Service (IaaS)

Cloud Service model that provides on-demand access to infrastructure such as servers, switches, and routers at rates based on resource use. Large-scale, global IaaS providers use virtualisation to minimise idle hardware, protect against data loss and downtime, and respond to spikes in demand.

Inheritance

In Object-Oriented Programming, Inheritance refers to the ability of an object to take on, or inherit, the properties of another object.

Institute of Electrical and Electronics Engineers (IEEE)

An American based professional associated, which develops standards for electronics and computer science.

Integrated Development Environment (IDE)

A piece of software that provides a means to create software and web applications. They generally include a source code editor, for programming purposes, a compiler where needed, for building an application and debugging tools, to aid in the resolution of bugs or problems with an application.

Integration Platform as a Service (iPaaS)

A subscription based service, which provides tools to enable the integration of data, applications and processes hosted on different physical and cloud services.

Intermediate Distribution Frame (IDF)

The room where all the horizontal runs from all the work areas on a given floor in a building come together.

Internet Control Message Protocol (ICMP)

A TCP/IP protocol used to handle many low-level functions such as error or informational reporting. ICMP messages are usually request and response pairs such as echo requests and responses or router solicitations and responses. There are also unsolicited 'responses' (advertisements) that consist of single packets. ICMP messages are connectionless.

Internet Group Management Protocol (IGMP)

Protocol that routers use to communicate with hosts to determine a 'group' membership to determine which computers want to receive a multicast. Once a multicast has started, IGMP is responsible for maintaining the multicast as well as terminating at completion.

Internet Information Services (IIS)

Web server software, that is provided by Microsoft and available on various versions of Microsoft Windows, including Windows 10 and Windows 11, as well as Windows Server.

Internet Message Access Protocol (IMAP)

Protocol for retrieving e-mail from an SMTP server.

Internet of Things (IoT)

The everyday objects that can communicate with each other over the Internet, such as smart home appliances, automobiles, video surveillance systems, and more.

Internet Protocol (IP)

Layer 3 protocol responsible for logical addressing and routing packets across networks, including the Internet. It doesn’t guarantee reliable delivery of packets across the network, leaving that task to higher-level protocols.

Internet Protocol Security (IPSec)

An encryption protocol that operates at layer 3, the network layer, of the OSI seven-layer model.

Internet Protocol version 4 (IPv4)

First version of the Internet Protocol introduced in 1980. IPv4 consists of a protocol, header, and address specification. Its 32-bit addresses are written as four sets of numbers between 0 and 255 separated by a period (often called dotted decimal notation).

Internet Protocol version 6 (IPv6)

Second version of the Internet Protocol developed as the address-space limitations of IPv4 became clear. While standardisation started in the 1990s, the transition from IPv4 to IPv6 is still ongoing. Its 128-bit addresses consist of eight sets of four hexadecimal numbers, with each number between 0000 and ffff, using a colon to separate the numbers.

Internet Service Provider (ISP)

An organisation that provides access to the Internet in some form, usually for a fee.

Internet Small Computer Systems Interface (iSCSI)

A protocol that enables the SCSI command set to be transported over a TCP/IP network from a client to an iSCSI-based storage system. iSCSI is popular with storage area network (SAN) systems.

Intrusion Detection System (IDS)

A system that monitors network traffic for suspicious activity and alerts when such activity is discovered.

Intrusion Prevention System (IPS)

A network security/threat prevention technology that examines network traffic flows to detect and prevent vulnerability exploits. Vulnerability exploits usually come in the form of malicious inputs to a target application or service that attackers use to interrupt and gain control of an application or machine.

JavaScript Object Notation (JSON)

A text-based data interchange format designed for transmitting structured data. It is most commonly used for transferring data between web applications and web servers.

Kerberos

A network authentication protocol developed by MIT to enable multiple brands of servers to authenticate multiple brands of clients.

Last In, First Out (LIFO)

A method of processing data in which the last items entered are the first to be removed.

Light-Emitting Diode (LED)

Solid-state device that emits photons at luminous frequencies when current is applied.

Lightweight Directory Access Protocol (LDAP)

A proprietary EAP authentication used almost exclusively by Cisco wireless products. LEAP is an interesting combination of MS-CHAP authentication between a wireless client and a RADIUS server.

Lightweight Directory Access Protocol (over SSL) (LDAPS)

A secure version of LDAP.

Link Aggregation Control Protocol (LACP)

IEEE specification of certain features and options to automate the negotiation, management, load balancing, and failure modes of aggregated ports.

Linux, Apache, MySQL, and PHP (LAMP)

The Linux operating system, Apache web server, MySQL database, and PHP web scripting language can be used together to create a fully functioning web server.

Local Area Network (LAN)

Network that generally (but not always) belongs to one household or organisation and covers a limited area (anything from two devices in an apartment up to thousands of devices on a multi-building school or business campus).

Local Connector (LC)

A duplex type of small form factor (SFF) fibre connector, designed to accept two fibre cables. Also known as LC connector or Lucent connector.

Logical Block Addressing (LBA)

An addressing scheme that acts as an interface between the operating system and storage devices. It presents storage chunks on a storage device to the operating system as a sequence of blocks. This saves the operating system from having to deal with the detail of how the storage space is arranged on a hard disk or solid-state disk. Logical Block Addressing is inherant to all operating systems and mass storage devices.

Long-Term Evolution (LTE)

A wireless data standard with theoretical download speeds of 300 Mbps and upload speeds to 75 Mbps. LTE is marketed as a 4G (fourth generation) wireless technology.

Mac OS, Apache, MySQL, and PHP (MAMP)

The Mac OS operating system, Apache web server, MySQL database, and PHP web scripting language can be used together to create a fully functioning web server.

Mail Exchange (MX)

A DNS record that SMTP servers use to determine where to send mail for a given domain.

Main Distribution Frame (MDF)

The room in a building that stores the demarc, telephone cross-connects, and LAN cross-connects.

Malware

Malware is the collective name given to software that has been developed to disrupt or damage data, software or hardware, as well as gain unauthorised access to computer systems.

Management Information Base (MIB)

A database used by the Simple Network Management Protocol (SNMP) to aid in the management of entities in a communication network.

Maximum Transmission Unit (MTU)

Specifies the largest size of a data unit in a communications protocol, such as Ethernet.

Mean Time Between Failure (MTBF)

A factor typically applied to a hardware component that represents the manufacturer’s best guess (based on historical data) regarding how much time will pass between major failures of that component.

Mean Time to Repair (MTTR)

The estimated amount of time it takes to replace or fix a failed system.

Mechanical Transfer – Registered Jack (MT-RJ)

A type of small form factor (SFF) fibre connector.

Media Access Control (MAC [1])

Unique 48-bit address assigned to each network card. IEEE assigns blocks of possible addresses to various NIC manufacturers to help ensure that each address is unique. The Data Link Layer of the OSI seven-layer model uses MAC addresses to locate machines.

Medium Access Control (MAC [2])

A protocol is used to provide the data link layer of the Ethernet LAN system.

Medium Dependent Interface Crossover (MDIX)

A version of the medium dependent interface (MDI) enabling a connection between corresponding devices. An MDI port or uplink port is a port on a switch, router or network hub connecting to another switch or hub using a straight-through cable rather than an Ethernet crossover cable. Generally, there are one to two ports on a switch or hub with an uplink switch, which can be used to alter between an MDI and MDIX interface.

Memorandum of Understanding (MOU)

A document that defines an agreement between two parties in situations where a legal contract is not appropriate.

Metropolitan Area Network (MAN)

Multiple computers connected via cabling, radio, leased phone lines, or infrared that are within the same city.

Model-View-Controller (MVC)

A design pattern utilised in software development, which is used to implement software interfaces, data and controlling logic, separating out the business logic from the display.

Multi-Function Device (MFD)

A single device that consolidates the functions of multiple document handling devices, such as printing, copying, scanning, and faxing.

Multiple Input, Multiple Output (MIMO)

Feature of 802.11n and later WAPs that enables them to make multiple simultaneous connections.

Multipoint Generic Routing Encapsulation (mGRE)

The Generic Routing Encapsulation (GRE) is a tunnelling protocol that can encapsulate several OSI layer 3 protocols. This protocol can be used by two endpoints to communicate with each other. It is developed by Cisco Systems, and can be used with IPSec to create a VPN. Multipoint GRE (mGRE) is a protocol that can be used to enable one node to communicate with many nodes.

Multiprotocol Label Switching (MPLS)

A routing technique in telecommunications networks that directs data from one node to the next based on labels rather than network addresses. Whereas network addresses identify endpoints the labels identify established paths between endpoints. MPLS can encapsulate packets of various network protocols, hence the multiprotocol component of the name.

Multiuser – Multiple Input, Multiple Output (MU-MIMO)

Feature of 802.11ac and later networking that enables a WAP to broadcast to multiple users simultaneously.

Mutable Object

A computer programming term used to describe an object whose state can change after it has been defined.

Name Server (NS)

DNS servers that hold the actual name and IP DNS records in a kind of database called a zone.

Network Access Control (NAC)

Control over information, people, access, machines, and everything in between.

Network Address Translation (NAT)

A way of converting a system's IP address into another IP address before sending it out to a larger network. A network using NAT provides the systems on the network with private IP addresses. The system running the NAT software has two interfaces, one connected to the network and the other connected to the larger network. The NAT program takes packets from the client systems bound for the larger network and translates their internal private IP address to its own public IP address, enabling many systems to share an IP address.

Network Attached Storage (NAS)

A dedicated file server that has its own file system and typically uses hardware and software designed for serving and storing files.

Network Function Virtualisation (NFV)

A network architecture that applies infrastructure as code (IaC) style automation and orchestration to network management.

Network Interface Card (NIC)

Traditionally, an expansion card that enables a PC to connect physically to a network. Modern computers now utilise built in NICs, without the need for a physical card, however, the term NIC is still very common.

Network Time Protocol (NTP)

Protocol that gives the current time.

Next-Generation Firewall (NGFW)

Network protection device that functions at multiple layers of the OSI model to tackle traffic no traditional firewall can filter alone.

Non-Disclosure Agreement (NDA)

A legally binding contract that establishes a confidential relationship. The party or parties signing the agreement agree that sensitive information they may obtain will not be made available to any others. An NDA may also be referred to as a confidentiality agreement.

Object Identifier (OID)

The Simple Network Management Protocol (SNMP) uses Management Information Bases (MIBs) to categorise data that can be queried, and subsequently analysed. Object Identifiers uniquely number data pieces within a MIB.

Object-Oriented Programming (OOP)

A programming paradigm based on the concept of “objects”, which may contain data, in the form of fields or attributes, and behaviours, in the form of procedures or methods. Computer programs created in this way are usually made up of multiple objects that interact with one another.

Open Shortest Path First (OSPF)

An interior gateway routing protocol developed for IP networks based on the shortest path first or link state algorithm.

Open Source

Software that is said to be open source refers to the fact that the original source code used to create it is made freely available to view, modify, enhance and redistribute.

Open Systems Interconnection (OSI)

An international standard suite of protocols defined by the International Organisation for Standardisation (ISO) that implements the OSI seven-layer model for network communications between computers.

Optical Time Domain Reflectometer (OTDR)

Tester for fibre-optic cable that determines continuity and reports the location of cable breaks.

Personal Area Network (PAN)

An interconnection of devices to facilitate the exchange of information in the vicinity of a person. This is over a short distance of less than 33 feet or 10 metres and typically utilises wireless technologies, such as Bluetooth.

Phishing

An attempt to gain sensitive information, such as user account and bank details, for malicious reasons, via an electronic communication, such as email, purporting to be from a trustworthy source. This might be to steal someone’s identity, for financial gain, or both.

Platform as a Service (PaaS)

A cloud service model which provides a managed environment of hardware and software. This type of service is popular with application developers as it removes the need to maintain the complex infrastructure required.

Pointer Record (PTR)

A type of DNS record that points IP addresses to hostnames.

Polymorphism

In Object-Oriented Programming, Polymorphism refers to the ability of a programming language to process objects differently depending on their data type or class.

Port

In Computing there are two types of port, hardware ports and networking ports. A hardware port serves as an interface between a computer and peripheral devices, such as a monitor, printer, keyboard and mouse. A port is a part of a computer that these devices connect to. A networking port is a communication endpoint. It is a logical construct that identifies a specific process or type of network service, at the software level, within an operating system. Ports have a port number associated with them and relate to specific transport protocols, for example, port 80 handles HTTP traffic.

Port Address Translation (PAT)

The most used form of network address translation, where the NAT uses the outgoing IP addresses and port numbers (collectively known as a socket) to map traffic from specific machines in the network.

Post Office Protocol version 3 (POP3)

One of the two protocols that receive e-mail from SMTP servers.

Power Distribution Unit (PDU)

A rack-mounted set of outlets for devices installed in the rack. Connected to the rack’s uninterruptible power supply (UPS).

Power over Ethernet (PoE)

A standard that enables wireless access points (WAPs) to receive their power from the same Ethernet cables that transfer their data.

Pre-Shared Key (PSK)

A shared secret which was previously shared between two parties using some secure channel before it needs to be used.

Quad Small Form-factor Pluggable (QSFP)

Bidirectional (BiDi) fibre-optic connector used in 40GbE networks.

Quality of Service (QoS)

Policies that control how much bandwidth a protocol, PC, user, VLAN, or IP address may use.

Radio Frequency (RF)

Oscillation rate of an alternating electric current or voltage or of a magnetic, electric, or electromagnetic field or mechanical system in the frequency range from around 20 KHz to 300 GHz.

Radio Guide (RG)

Ratings developed by the US Military to provide a quick reference for the different types of coaxial cable.

Random Access Memory (RAM)

Memory that can be accessed randomly, either for reading or writing, without accessing preceding parts of it.

Read-Only Memory (ROM)

Memory that can be read from but to written to. Often described as non-volatile memory.

Real Time Streaming Protocol (RTSP)

An application-level network protocol designed for multiplexing and packetising multimedia transport streams (such as interactive media, video, and audio) over a suitable transport protocol. RTSP is used in entertainment and communications systems to control streaming media servers. The protocol is used for establishing and controlling media sessions between endpoints. Clients of media servers issue commands such as play, record, and pause, to facilitate real-time control of the media streaming from the server to a client (video on demand) or from a client to the server (voice recording).

Received Signal Strength Indication (RSSI)

A scale used by manufacturers to show the signal between a WAP and a receiver, usually depicted in a number of bars.

Recovery Point Objective (RPO)

An upper limit to how much lost data an organisation can tolerate if it must restore from a backup. Effectively dictates how frequently backups must be taken.

Recovery Time Objective (RTO)

The amount of time needed to restore full functionality from when the organisation ceases to function.

Redundant Array of Independent or Inexpensive Disks (RAID)

A method for creating a fault tolerant storage system. RAID uses multiple hard drives in various configurations to offer different levels of speed and data redundancy.

Registered Jack (RJ)

Type of connector used on the end of telephone (RJ-11) and network cables (RJ-45).

Remote Authentication Dial-In User Service (RADIUS)

A system that enables remote users to connect to a network service.

Remote Desktop Protocol (RDP)

Protocol used for Microsoft's Remote Desktop tool.

Request for Comment (RFC)

A document that describes the standards, protocols, and technologies of the Internet and TCP/IP. Since 1969, about 2400 Requests for Comments (RFCs) have been published on various networking protocols, procedures, applications, and concepts.

Router Advertisements (RA)

On multicast-capable links and point-to-point links, each router periodically sends to the multicast group a router advertisement packet that announces its availability. A host receives router advertisements from all routers, building a list of default routers. Routers generate router advertisements frequently enough so that hosts learn of their presence within a few minutes. However, routers do not advertise frequently enough to rely on an absence of advertisements to detect router failure. A separate detection algorithm that determines neighbour unreachability provides failure detection.

Routing Information Protocol (RIP)

A routing protocol. Version 1 had several shortcomings, with a maximum hop count of 15 and a routing table update interval of 30 seconds, causing every router on a network to send out its table at once. Version 2 added support for CIDR and fixed some of the issues with version 1, but maximum hop count remained.

Secure File Transfer Protocol (SFTP)

Uses SSH to provide the encryption for secure file transfer.

Secure Shell (SSH)

An encrypted remote terminal connection program, used to remotely connect to a server. SSH uses asymmetric encryption, however, it generally requires an independent source of trust with a server, such as manually receiving a server key, to operate.

Secure Sockets Layer (SSL)

A protocol developed for transmitting private documents over the internet. It works by using a public key to encrypt sensitive data. This encrypted data is then sent over an SSL connection and then decrypted at the receiving end using a private key. Deprecated by Transport Layer Security (TLS).

Security Information and Event Management (SIEM)

A two-part process consisting of security event management (SEM), which performs real-time monitoring of security events and security information management (SIM), where the monitoring log files are reviewed and analysed by automated and human interpreters.

Server Message Block (SMB)

Protocol used by Mircrosoft clients and servers to share file and print resources.

Service Level Agreement (SLA)

A document between a customer and service provider that defines the scope, quality, and terms of the service to be provided.

Service Record (SRV)

DNS record that associates servers for individual protocols with a domain. SRV records specify a host, port, protocol, and other details for a specific service. For example, VoIP clients can readily discover a domain’s associated SIP server.

Service Set Identifier (SSID)

A 32-bit identification string, sometimes called a network name, that’s inserted into the header of each data packet processed by a wireless access point.

Session Initiation Protocol (SIP)

A signalling protocol for controlling voice and video calls over IP.

Shielded Twisted Pair (STP)

A Special kind of copper telephone and Local Area Network wiring that adds an outer layer, or shield, to reduce the potential for electromagnetic interference. Twisted pair wiring is where two conductors of a single circuit are twisted together to improve electromagnetic compatibility.

Simple Mail Transfer Protocol (SMTP)

The main protocol used to send email over the internet.

Simple Network Management Protocol (SNMP)

A set of standards for communication with network devices, such as switches and routers, connected to a TCP/IP network. Used for network management.

Single Sign-On (SSO)

A process whereby a client performs a one-time login to a gateway system. That system, in turn, takes care of the client’s authentication to any other connected systems for which the client is authorised to access.

Single-Board Computer

A computer built on a single circuit board, which incorporates a processor, memory, input and output capabilities, along with many other features of a regular computer.

Small Form-factor Pluggable (SFP)

A Cisco module that enables you to add additional features to its routers.

Small Office Home Office (SOHO)

A classification of networking equipment, usually marketed to consumers or small businesses, which focuses on low price and ease of configuration. SOHO networks differ from enterprise networks, which focus on flexibility and maximum performance.

SMShing

An attempt to gain sensitive information, such as user account and bank details, for malicious reasons, via an SMS message, purporting to be from a trustworthy source. This might be to steal someone’s identity, for financial gain, or both.

Social Engineering

The use of deception to manipulate an individual into divulging confidential or personal information that may be used for fraudulent purposes.

Software as a Service (SaaS)

Cloud service model that provides centralised applications accessed over a network.

Software Development Kit (SDK)

A collection of software development tools that facilitate the creation of software, which can include a software framework, compiler and debugger.

Software Development Lifecycle (SDLC)

A process used by the software industry to design, develop and test high quality software. The Software Development Life Cycle typically consists of stages such as, planning and requirements analysis, definition of requirements, design, build, test, deploy and maintain. There are a number of different Software Development Life Cycle models that are used today, including the waterfall model, the iterative model, the spriral model, the V-medel and the big bang model.

Software-Defined Network (SDN)

Programming that allows a master controller to determine how network components will move traffic through the network. Used in virtualisation.

Software-Defined WAN (SDWAN)

A wide area network that uses software-defined network technology, such as communicating over the Internet using overlay tunnels which are encrypted when destined for internal organisation locations.

Solid-State Drive (SSD)

Data storage device that uses flash memory to store data.

Spanning Tree Protocol (STP)

A protocol that enables switches to detect and prevent switching loops automatically.

Spoofing

Spoofing is a fraudulent or malicious activity whereby a communication is sent from an unknown source disguised as a source that is known to the receiver. E-mail spoofing is a particular type of spoofing where the header of an e-mail is forged to appear as though it from a particular sender, but instead is from an unknown source.

Standard Connector (SC)

Fibre-optic connector used to terminate single-mode and multimode fibre. It is characterised by its push-pull, snap mechanical coupling, known as 'stick and click'. Commonly referred to as subscriber connector, standard connector, and sometimes, Siemon connector.

Start of Authority (SOA)

DNS record that defines the primary name server in charge of a domain. Also includes parameters that control how secondary name servers check for updates to the zone file, such as the serial number which indicates whether the zone file has updates to fetch.

Stateless Address Auto-Configuration (SLAAC)

A process that enables network clients to determine their own IPv6 addresses without the need for DHCP.

Storage Area Network (SAN)

A server that can take a pool of hard disks and present them over the network as any number of logical disks.

Straight Tip or Snap Twist (ST)

Fibre-optic connector used primarily with 2.5 mm single-mode fibre. It uses a push-on, then twist-to-lock mechanical connection commonly called stick-and-twist although ST actually stands for straight tip.

Structured Query Language (SQL)

A language created by IBM that relies on simple English statements to perform database queries. SQL enables databases from different manufacturers to be queried using a standard syntax.

Supervisory Control and Data Acquisition (SCADA)

A system that has the basic components of a distributed control system (DCS), yet is designed for large-scale, distributed processes and functions with the idea that remote devices may or may not have ongoing communication with the central control.

Switch

An electronic device that provides a common point for the connection of network devices, which replaced Hubs. A switch will learn the MAC address of all connected devices when they first connect. This means that it can forward data to the correct device, rather than to all connected devices, as with a Hub.

System Log (SYSLOG)

System log collector in macOS and Linux. Useful for auditing, performance monitoring, and troubleshooting.

Telecommunications Industry Association/Electronic Industries Alliance (TIA/EIA)

The standards body that defines most of the standards for computer network cabling. Many of these standards are defined under the ANSI/TIA-568 standard. Since the Electronics Industry Association (EIA) was accredited by the American National Standards Institute (ANSI) to develop the standards, the name changed from TIA/EIA to ANSI/TIA after the EIA closed in 2011.

Temporal Key Integrity Protocol (TKIP)

A deprecated encryption standard used in WPA that provided a new encryption key for every sent packet.

Terminal Access Controller Access Control System Plus (TACACS+)

A proprietary protocol developed by Cisco to support Authorisation, Authentication, and Accounting (AAA) in a network with many routes and switches. It is like RADIUS in function but uses TCP port 49 by default and separates AAA into different parts.

Time to Live (TTL)

A field in the IP header that indicates the number of hops a packet can make before it hits its demise and gets discarded by a router.

Transmission Control Protocol (TCP)

A Layer 4 connection-oriented protocol within the TCP/IP suite. TCP provides a reliable communications channel over an unreliable network by ensuring all packets are accounted for and retransmitted if any are lost.

Transmission Control Protocol/Internet Protocol (TCP/IP)

A set of communication protocols, developed by the U.S. Department of Defence, which enable dissimilar computers to share information over a network.

Transmit and Receive (TX/RX)

Abbreviations used for transmit and receive.

Transport Layer Security (TLS)

A protocol where hosts use public-key cryptography to securely negotiate a cipher and symmetric key over an unsecured network, and the symmetric key to encrypt the rest of the session. TLS is the current name for the historical SSL protocol.

Trivial File Transfer Protocol (TFTP)

A protocol that transfers files between servers and clients, without the need for user login. Devices that need an operating system, but have no local hard disk (for example, diskless workstations and routers), often use TFTP to download their operating systems.

Ultra-Physical Contact (UPC)

Fibre-optic connector that makes physical contact between two fibre-optic cables. The fibres within a UPC are polished extensively for a superior finish and better junction integrity.

Uniform Resource Locator (URL)

An address that defines the type and the location of a resource on the Internet. URLs are used in almost every TCP/IP application.

Uninterruptible Power Supply (UPS)

A device which provides continuous power to a computer system whilst it is powered on. It protects against power outages.

Universal Serial Bus (USB)

A common interface that enables communication between devices and a host controller such as a personal computer (PC) or smartphone. It connects peripheral devices such as digital cameras, mice, keyboards, printers, scanners, media devices, external hard drives, and flash drives. Because of its wide variety of uses, including support for electrical power, the USB has replaced a wide range of interfaces like the parallel and serial port.

Unshielded Twisted Pair (UTP)

A popular cabling for telephone and computer networks composed of pairs of wires twisted around each other at specific intervals. The twists serve to reduce interference, or crosstalk, as it is sometimes known. The more twists, the less interference. The cable has no metallic shielding to protect the wires from external interference, unlike Shielded Twisted Pair (STP). UTP is available in a variety of grades, called categories.

User Datagram Protocol (UDP)

Connectionless protocol in the TCP/IP suite. Has less overhead and better performance than TCP, but also a higher risk of errors. Fire-and-forget UDP datagrams do a lot of important behind-the-scenes work in a TCP/IP network.

Virtual IP (VIP)

A single IP address shared by multiple systems. This is commonly the single IP address assigned to a home or organisation that uses NAT to have multiple IP stations on the private side of the NAT router. Virtual IP addresses are also used by the First Hop Redundancy Protocol (FHRP).

Virtual Learning Environment (VLE)

A system for delivering learning material via the web. Its purpose is not to replace face to face teaching, but to enhance it, with the use of various activities that they provide. VLEs are also a means to share resources with its users, such as files and web links.

Virtual Local Area Network (VLAN)

A common feature among managed switches that enables a single switch to support multiple Layer 2 broadcast domains and provide isolation between hosts on different VLANs. Critical for modern network performance and security.

Virtual Machine (VM)

A virtual computer accessed through a class of programs called a hypervisor or virtual machine monitor. A virtual machine runs inside your actual operating system, essentially enabling you to run two or more operating systems at once.

Virtual Network Computing (VNC)

A remote access program and protocol.

Virtual Network Interface Card (vNIC)

Software-based NIC that functions identically to a physical NIC and uses a software connection to pass traffic from the real. NIC to the virtual one.

Virtual Private Network (VPN)

A network configuration that enables a remote user to access a private network via the Internet. VPNs employ an encryption methodology called tunnelling, which protects the data from interception.

Virtual Router Redundancy Protocol (VRRP)

Open standard FHRP that provides high availability by taking multiple routers and grouping them together into a single virtual router with a single IP address that clients use as a default gateway.

Vishing

An attempt to gain sensitive information, such as user account and bank details, for malicious reasons, via the telephone, purporting to be from a trustworthy source. This might be to steal someone’s identity, for financial gain, or both.

Voice over Internet Protocol (VoIP)

The use of an IP network to conduct voice calls.

Wavelength Division Multiplexing (WDM)

In fibre-optic communications, wavelength-division multiplexing (WDM) is a technology which multiplexes several optical carrier signals onto a single optical fibre by using different wavelengths (i.e., colors) of laser light. This technique enables bidirectional communications over a single strand of fibre, also called wavelength-division duplexing, as well as multiplication of capacity.

Wi-Fi Protected Access (WPA)

A wireless security protocol that addresses weaknesses and acts as an upgrade to WEP. WPA offers security enhancements such as dynamic encryption key generation (keys are issued on a per-user and per-session basis), an encryption key integrity-checking feature, user authentication through the industry standard Extensible Authentication Protocol (EAP), and other advanced features that WEP lacks. WPA has been replaced by the more secure WPA2.

Wi-Fi Protected Access 2 (WPA2)

Consumer name for the IEEE 802.11i standard and the replacement for the WPA protocol. It uses the Advanced Encryption Standard, making it harder to crack than its predecessor.

Wi-Fi Protected Access 3 (WPA3)

Wireless encryption standard that is replacing WPA2. Uses Simultaneous Authentication of Equals (SAE), a key exchange based on Diffie-Hellman that generates unique encryption keys between each client and WAP.

Wide Area Network (WAN)

A geographically dispersed network created by linking various computers and LANs over long distances, generally using leased phone lines. There is no firm dividing line between a WAN and a LAN.

Windows, Apache, MySQL, and PHP (WAMP)

The Windows operating system, Apache web server, MySQL database, and PHP web scripting language can be used together to create a fully functioning web server.

Wireless Access Point (WAP)

Connects wireless network nodes to wireless or wired networks. Many WAPs are combination devices that act as high-speed hubs, switches, bridges, and routers, all rolled in to one.

Wireless Local Area Network (WLAN)

A network that allows devices to connect and communicate wirelessly.

World Wide Web Consortium (W3C)

An international body that maintains web-related rules and frameworks, comprising of over 350 member organisations, which jointly develop web standards, run outreach programs, and maintain an open forum for talking about the Web.