I've recently started to study networking, and how to do very simple servers and clients using Java. I'm understanding the material just fine, but for some reason, I can't find any material on how to actually implement a real server. What I mean is that all the tutorials that I find only tell me how to set up the server and client from my own computer. I always have to tell the client program to look for the server localhost, because the server is run from the same computer. This is fine for testing, but if I wanted to start an actual server on my computer which can provide information to a client from outside of my house, like a friend's house, how would I do this?