Poll: is 2 core better than a 4 core processor?

A core is a processor - the part of the computer that actually does the work. When you have a "dual" core, then the chip that serves as the "brain" of your device actually has two processors working side-by-side. A quad-core processor has four. Except in certain (very rare) circumstances, four brains are better than two :-)

The ghz numbers are the number of instructions being processed per second; in general, the higher than number is, the more work your computer is doing, and the faster your program (in this case, a game) can run.

For my money, I'd rather have excess computing power than not enough. I'm not a gamer, but there are other things that require a lot of processor access (video in general is a good example, as can be audio), so I'd rather have power to burn than to run out and be limited by my processor's speed.

Other than having a fast processor, the best thing you can do to speed up your computer is to put as much memory in it as it can handle. And by "memory," I mean internal memory, not hard drive space. I'd have to get pretty technical to explain why, but suffice it to say that the more memory you have, the less often your computer has to access a hard drive, which is one of the SLOWEST things a computer does because it's a physical process rather than an electronic one the vast majority of the time.