Server computer? Newb question

What exactly is a server computer used for?
Can you make a server computer with a mini itx board?

How much processor power, ram power, hardrive power needed?

What can it be used for? Can it be used to host my own website? Host own game servers?

Will I need a seperated internet connection than from the one I use for daily use (gaming). Will it have to be an amazing internet connection say 50mb/s?

Not being sarcastic, but a server literally "serves" information; hence the name. For home use, it could simply be a single location to house your files and provide access to the rest of the network. You could run web servers, databases, virtual machines and anything else you can think of. The things you can do with servers are absolutely incredible.

You can run a server on any hardware, just be sure that it meets your need. For example, if you are running a game server, make sure it has the processing power so it doesn't cause lag or slowness. You could host your own web site, but you'd want to check with your ISP to verify they allow you to do this -- some don't.

For a connection, you can use whatever you want, as long as it is connected to what it needs to be. Meaning, if this is for an internal network, it doesn't actually need an internet connection. If you are hosting external facing application (web servers, game servers, etc), then it will need an internet connection. How fast of one depends on what you are providing.

There is nothing special about the hardware or connection for a server, it is literally just another computer doing very specific tasks.

I see this actually explained everything for me. I've searched it up before but people describe it differently and use different words instead of just getting str8 to the point of what it does. Thanks man!