Since Android is linux based it can be modified to allow root access giving programs low level access to the operating system, which they normally wouldn't have. The process on rooting depends on the phone. By the way, if you decide to go with a Droid I highly recommend the HTC phones.
It's not that difficult to root but if you have any techie friends you may want to seek their help. It's a one time process. Once rooted you can download wireless tether and that will allow you to share your phone's internet access FOR FREE with any other wireless device...laptop, ipad, etc. Wireless tether on the LTE (4G) network is awesome.
