What exactly does convolution mean?

Benjamin F explained it pretty well, but if you need another explanation (I know it's a really weird math concept) try this website. The last entry is a pretty good explanation: a href="http://forums.xkcd.com/viewtopic.php?f=18&t=29712" rel="nofollow"http://forums.xkcd.com/viewtopic.php?f=1…/a