Computer Learning

[D-More-D-Better]

Two PCs: Can anyone help or tell me where to get info on the following. I'm looking to get a second computer (or revamp my older one) to connect with my present one so my kids can play a game called Command & Conquer Generals against each other in the same room. The box on the game says for multiplayer games you need either internet connection or network connection (TCP/IP.) Does a PC usually come with the necessary ports for the network connection (so all I need to buy is a cable or wire)? Or do I need to buy a few different things? Thanks for any help.