What does this question even mean (no I don’t want to listen to a podcast to find out)?

Sometimes I think people have been using the term “self-hosted” to mean what we used to call a home PC. I have always thought of a hosted computer (whether self-hosted or hosted by a company) as meaning a server which normally would live in a data center, and sometimes even means a rented box or VPS on which you self-host by installing and managing the software yourself (as opposed to using managed hosting or cloud services). Of course if you have good enough internet, you can self-host a server at home, but the considerations are otherwise about the same. I.e. it would usually not also be your workstation or gaming box.

So what is it that your friends are going to do with the machine? That would be pretty important in figuring out how to prepare it.