Why not? And, no offence, but why should I care? Maybe give details if you’re bothered enough to post.

The basic answer to that is that it gives you administrator access to your phones operating system, in the exact same way as you would have by logging into your desktop computer as an administrator rather than a normal user. Handle with care!

In this mode we can have full access to parts of the phone’s operating system that are usually restricted to a normal user. On android this means we can install apps that require the phone to be rooted. For example, with these apps we can have access to /system folder and mount as writeable, or install a firewall app that uses linux/android’s iptables.

If you want more specific information google is your friend, but here is an article from lifehacker for some good examples (http://lifehacker.com/top-10-reasons-to-root-your-android-phone-1079161983).

But I must stress that it’s not for everybody!!! You can seriously mess up your phone if you do not know what you are doing, for example, accidentally uninstalling critical android apps rendering your phone unbootable.

Happy rooting!