Apple will no longer let users roll their iPhone operating systems (iOS) back to previous versions to prevent them from jailbreaking the smartphone. Apple plans on implementing the new security feature as soon as iOS 5 is launched.
The term jailbreaking means to hack your operating system so you can unlock special features, software capabilities, and sometimes hardware capabilities as well. The good news is that the security feature will only be installed in versions iOS 5 and future versions of the iOS. iOS 4 will still be able to be jailbroken as well as any Apple devices of the current generation or a previous generation.