Take a look at your computer now. The same thing happens on the other side of that front of your case. There's a power supply in there somewhere with several cables in bundles of four coming out of it. There are also cables that go from the power supply to the motherboard. Look a little more carefully and you can identify the CPU chip, probably with a tiny fan desperately trying to keep the chip and surrounding area from melting down, memory chips on strips called SIMS or DIMS rising at right angle out of the mother board, and component cards neatly arranged along the back of the motherboard.
Parts is parts.
However, there is a caveat that must be talked about here. Getting into computers up to your elbows is not for the faint of heart. I know there isn't a person alive who works on computers who hasn't had that terrible feeling of utter doom when they realize they've made a really stupid mistake. One evening at home in the tiny corner of the laundry room where I work on computers, I installed a CPU chip in the wrong direction in the slot on the motherboard. I was tired and lost my concentration.