system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What does each part of a computer actually do?

This Summer, with the help of a good friend (genius with computers) I built my own computer.  I have a vague understanding of what each component does, however at the same time, I get extremely confused.

So I'm asking, what does each component of a computer (Ram, Processor etc) actually do?

Thanks!
gpt
Motherboard: Connects everything together.

RAM: Stores information for the processor, reads and writes REALLY fast

Processor: Makes decisions, runs programs. The 'heart' of your computer.

Hard Disk/SSD: Stores stuff when computer is off. Slower then RAM.

GPU: Renders 3d graphics and does parallel computing type stuff. Primarily just Renders 3d graphics.

Sound Card: Decodes sound better then your CPU, also can help provide 3d sound for games that support it. Also gives 'higher quality' sound then your motherboard.

Anything else?

CD/DVD/Bluray: Basically a hard-drive that's even SLOWER but transportable (and shiny).

PSU/Power Supply: Supplies Power.