- last post: 01.01.0001 12:00 AM PDT
Unless you got your computer very recently, it's almost certainly AGP. So, make sure the card is AGP compatible.
The memory (64, 128, or 256MB) is where the card stores textures and the like while your actually playing the game. The more you have, the easier it will be for your card to let you use bigger and prettier textures. Still, most games still don't really need more than 128, so you can forego the other 128MB for now, but it won't last you.
The core and memory clock speeds are basically the speed of the card. The higher, the better. These can be raised if you want to overclock, but since you know so little don't buy a card thinking you can do this.
If you want to play Halo on your computer monitor, you're going to want a card that supports Video In/Video Out, which may be called VIVO.