What is on my Olympus E-PL1 Lens?

I am new to DSLR's (I know this is a CSC). Anyway, on the lens (which by the way, is it lens or lense) is the ring that changes from 14 to 42. In front of that is another ring that moves. What does that ring do? To those who do not know what I am talking about look at this link http://www.techshout.com/reviews/2010/07/olympus-pen-e-pl1-camera-review-capturing-the-surrounding-with-a-surreal-offering/ and the ring closest to the left in the picture is what I am talking about. Thanks