Can you use server components in a regular pc?

I took a contracted Electronics Recycling job, and after the job, the guy gave me 3 server computers because he said he wouldn't be able to make any money off of them.

I'll be using 1 to set up a home server and practice server maintenance and configuration for getting a job, and I'm not sure what to do with the other 2.

I was considering salvaging the parts in one of them to upgrade my PC if the parts are compatible. Specifically I'm looking to see if the Hard Drive, RAM, and GPU are compatible, because those are what I want to upgrade.

So do server computers and regular pcs use completely compatible parts? I mean obviously every pc is different but in general, should I be able to use server parts in a pc?