2. CPU

The CPU is the engine of your computer and sets the performance expectations for the entire build. The CPU provides the processing power and instructions behind all your computer’s operations.

This is the brain of your computer. It sockets directly into the motherboard, and it’s the single most important component of your PC, it solves all the sophisticated algorithms and programming your computer does while running programs or applications

CPU means Central Processing Unit and it processes any task that you might throw at it. Without it, the computer won’t work.

Almost everything you do on a computer will have to be calculated by the CPU in some way, so having a fast CPU (high frequency and high core count) will make your PC faster

There are some webs where you can buy one:

https://www.bestbuy.com/site/computer-cards-components/computer-pc-processors/abcat0507010.c?id=abcat0507010

https://www.cclonline.com/pc-components/cpu-processors/

And how to install it:

https://www.digitaltrends.com/computing/how-to-build-a-pc/

How a CPU works?

CPU should cost between $130 and $350