It's just a way to recognize your computer on a network. If you don't have a network, don't share files, it really doesn't matter, as you will never use the computer name. But if I want a file off the computer upstairs, I need to know it's name to find it.

You are not locked into it, you can change it any time you want.

Over the years I've seen many schemes, one place did all animal names, another did all street names and the servers were neighborhoods, etc. At my first job the person who set it up was a huge Three Stooges fan, the servers were all Moe, Larry, etc.