Newbie Question-Rooting

[BJones]

I tried to search the site looking for an explanation of rooting and its benefits/non-benefits. I came across several threads, just nothing that helps me understand what rooting is and what it does. I've seen a lot about it as it pertains to making the droid faster and/or perform better. Can anyone give me the 'down and dirty" concerning how to tell if my droid is rooted or not, what rooting is, what it does, and the benefits/non-benefits? Or, point me in the right direction if there is already a thread here that discusses this. Please forgive my "Newbieness!"