iOS 7 is the seventh major release of the IOS mobile operating system designed by Apple Inc and successor of iOS 6. It was announced at the company's Worldwide Developers Conference (WWDC) on June 10, 2013, and was released on September 18, 2013. iOS 7 features a completely redesigned user interface, a design credited to a team led by Apple's SVP of design Sir Jonathan Ive.
iOS 7 was succeeded by iOS 8, which was released on September 17, 2014. The final version of iOS 7 is 7.1.2.
IOS 8 is the eighth generation of the IOS mobile operating system designed by Worldwide Developers Conference on June 2 2014, and released on 17 September 2014.
Since the IOS 8 released, IOS users who stay on ios version 7 - 7.0.6 can not jailbreak them device any more. If they want Jailbreak them devices they must update devices to ios 8 then jailbreak it.