iOS
iOS is a mobile operating system, developed by Apple that is used exclusively in Apple hardware. It was first released back in 2007 for use in the iPhone, under its original name of iPhone OS, but has since been extended to include the iPod Touch, iPad and iPad Mini, as well as second generation Apple TV.
Today Apple’s App Store contains over 1.4 million iOS applications.
iOS File System
iOS utilises the Apple File System, or APFS for short, which is a proprietary file system from Apple. It is optimised for Flash and SSD storage, with features including strong encryption, snapshot functionality and fast directory sizing, to name a few.
Each iOS app runs in its own sandbox, meaning that no app can access the data of another app. The sandbox is split into three containers, the Bundle Container, that houses the apps functionality, the Data Container, for any documents, libraries and temporary data, and finally, the iCloud Container, to handle anything associated with iCloud.
iOS makes extensive use of Plists and SQLite databases for the management of configuration information and other data, such as Contacts and SMS messages.
Plists come in two forms, they are either XML or binary based. The former can be opened using a simple text editor, whilst the latter requires a hex editor, such as HxD.
SQLite databases are used throughout the file system for storing various items of data such as text messages, contacts and voicemail entries and can be accessed using graphical tools such as DB Browser for SQLite and SQLiteStudio.