In talking about hardware components, we've covered computer cases, tools of the trade, monitors, keyboards, mice, hard drives, and DVD drives. These components can be pretty much purchased independently of the rest of the system components.
We are about to get into the heart of the computer, and talk about power supplies, graphic cards, cpu chips, and finally motherboards. All of these components inter-relate with one another. For example, if you purchase a computer chip it mates to a particular type of socket on the mother board, so you need to be careful when you purchase your motherboard that it comes with that socket.
Do not purchase one of these components until after you read about all of them. Each component has to mate with the other components in your system. And if your careful, you'll find that everything will come together neatly, if your not, you'll be exchanging and returning parts. A royal pain.
At the end of the hardware components, I'll summarize everything you'll need to buy with cautions about what you need to make sure you have with the part you purchase.