The graphics card is a piece of hardware that handles the bulk, if not all, of the video processes for the PC's applications, thus freeing up the CPU to handle everything else. The better the graphics card, the smoother and more detailed the games will look. If your PC is the one I looked at on gateway's site, you've got a GeForce 6600 128MB card in there which, while not top-of-the-line, is still a really nice card.
"Caw, caw, *BANG* FUCK I'M DEAD!" - Top Dollar, The Crow
"Physics is like sex: It may yield practical results, but that's not why we do it." - XKCD
God created whiskey to stop the Irish from taking over the word.