Emulating has to do with taking the image (not a picture, but rather, the game information) from a game, and using it in conjunction with a program that mimics the coding of a game system. Essentially, this means you can play any game that goes onto a cartridge, on your computer, as long as you download the ROM, or the eqiuvalent of a game in coded form.

ROM = game;
Emulator = System;
both are on the PC and available for download

The first six can be emulated (there are sites where you can download both ROMs and Emulators, but since they are mostly illegal without you having a legitimate copy of the game, I will not mention them here). VII and VIII can be played with their PC versions. IX can be emulated, but it is of poor and terrible quality, and time consuming, and probably costs more than getting a new PS2.

However, FFX does require that you have a PS2; there is NO WAY TO PLAY FFX ON THE COMPUTER.

FFXI is on the computer, but it is an MMORPG (think World of Warcraft, but nowhere near as cool, or think of Everquest II, except, better).