Nowadays you might have heard lots of about these 3 words, Jailbreak, Root, and Unlock, some of you might consider same or many of you get confused in these, all 3 has different meaning and work. Let see each one by one.
Rooting is mainly used in Linux devices like Android. Rooting means gaining root access of your device. Root users is same like Administrator users which means Root users can perform all task, grant root access to any application so that they can perform almost any task on your device like uninstall any system apps and so on.
Manufactures don’t want users get Root Access that’s why Android devices wont comes with root access out of box
Jailbreak term is mainly used in iOS devices like iPad or iPhone. Apple allows its users to install apps only from its app store which are approved by Apple itself, any app which is not present in Apples iTunes store cant be installed on iDevice.
If you want to install third party apps on your iDevice then you have to Jailbreak it. So in simple word you can say jailbreak is the process of removing limitation which is imposed by manufacturer on device.
Jailbreak not only allows you to install third party apps on your iDevice but you can also change your default browser, mail client and so on.
Jailbreak is not only for iOS devices but recently we had seen Jailbreak for Windows 8 RT tablets which also allows you to by pass restriction imposed by Microsoft.
Most of the times manufacturers launched their product in tie-up with some carriers (like Apple do most of the time in US) so that if any users buys its device then it has to be in contract, these devices in contract comes locked which means you cant use any other SIM until you finish your contract or pay to carrier.
If you use any other carrier SIM card then you will see a message is flashed saying YOU CANT USE THIS SIM CARD.
Unlocking allows you to use any other SIM in your device without completing contract and without paying your carrier too.