What is iOS?
Apple iOS is Apple’s Operating System running on mobile devices like iPhone, iPod Touch, iPad, also Apple TV. iOS (previously called as iPhone OS) developed for the iPhone at the first time, the Apple extended the iOS function to support other Apple iDevices such as the iPad, iPod touch, and Apple TV.
At the first time introduced, Apple marketing did not specify any name, people just say it is “OS X running on iPhone”. On March 6, 2008, Apple released the first beta version, along with a new name for the operating system called iPhone OS. Then, Apple rebranded iPhone OS as iOS in June 2010 and licensed the “IOS” trademark from Cisco because the trademark “IOS” had been used by Cisco for over a decade for their router operating system.
Where to download Apple iOS firmware file?
By default, you will be notified by iTunes whenever new iOS version released. To download older iOS versions, please browse our archives for Download iPhone Firmware topic.
The format of iOS firmware file is .IPSW