Every computer has a central processor or CPU, be it a tiny tablet or a hulking workstation, but when it comes to desktop gaming PCs, oh boy is there a lot to choose from. Despite there being only two vendors in the whole market, you've got hundreds of different models vying for your attention.
Browse through the listings of any major retailer, and you'll be faced with three to four generations worth of chips from AMD and Intel. You can get them with just four or six cores, to as many as 24.