What is iOS?
iOS is a mobile operating system developed by Apple Inc. and distributed exclusively for Apple hardware. It is the operating system that powers iPhone, iPod Touch, and formerly iPad.
Each main version of iOS / iPhone OS has introduced a big, main feature of the new version.
- iPhone OS 1 was the original "iOS", and had only first-party Apple, preinstalled apps such as "Phone", "iPod", and "Safari".
- iPhone OS 2 introduced the App Store that we know today.
- iPhone OS 3 added in copy and paste functionality, several Google-licensed apps (Maps and Youtube), as well as basic tethering functions.
- iOS 4 brought in multitasking and Wallpaper-changing. iOS 4 also dropped the original iPhone from it's supported devices, and the iPhone 3G held limited support.
- iOS 5 introduced several new features, such as iMessage, Newsstand, Reminders, Twitter integration, iCloud, and a beta of Siri.
- iOS 6 fully released Siri and Siri Eyes Free, brought in Passbook and Facebook integration, as well as Apple-sourced maps instead of Google sourced, marking the removal of the Youtube app as well.
- iOS 7 held a massive design overhaul, turning skeumorphic into modern and flat. Also brought in a "Control Center" which offered a quick-access area for commonly used features (flashlight, wifi on/off, bluetooth on/off, calculator app, etc.).
- iOS 8 introduced the Health App, which enables data-mixing from all kinds of fitness apps, from MyFitnessPal to Misfit. iMessages gained voice messaging, and Indoor Mapping with the iPhone 5S, 6, and 6+'s M7 and M8 coprocessors.
- iOS 9 introduced a new multitasking features on iPad, new Notes features, the iCloud Drive app, HomeKit integration, Apple Maps improvements.
- iOS 10 incorporated changes to 3D Touch and the lock screen. There were new features to Messages, Maps, Photos and Siri.
- iOS 11 had significant design changes: combined lock screen and Notification Center, Appstore restyle, translation between languages for Siri, screen recording.