On this basic video tutorial by Canon, photographer Matt Kloskowski takes a look at the basics of lenses.
The video starts by some common lingo, so if you are just starting with photography this should help you get into the common language photographers use when talking about their lenses.
On the video Kloskowski mentions the topic of aperture several times. Its a good time as any to be reminded by this video (also from the the Canon 101) by Brian Dilg on the Aperture:
These videos are part of Canon’s EOS 101 basic tutorial series which you can view as it is updated here on LensVid.