@Kuriyama - Nice metaphor.
So what do you people usually do with your servers? Why did you get one, and for what purpose?
So here's another thing I've been curious about. What's the difference between the different server types (ex. Apache, IIS, etc.)?
Well you are talking about 2 different things. Apache,IIS are web servers, but they aren't hardware.
Typical network diagrams have a domain controller, second domain controller, file share system, FTP server, Web Server. . . etc.
Apache vs IIS
Apache is an open source web server that has been around for a long time. It has a lot of nice features such as rewrite mods (.htaccess file), and it works on all OS's out there.
IIS is a microsoft web server that only runs on microsoft OS's (to the best of my knowledge). IIS comes in a lot of different flavors and isn't as robust as Apache IMO. For instance there is no rewriting tools out of the box, unless you are using IIS 7.0. Don't even bother using IIS unless you are planning on purchasing and running a Microsoft Server Addition OS. One big advantage of IIS is that it's very easy to use the .NET framework.
At the end of the day they more or less do the same thing, and really it's about what server side language you want to develop with.
.NET or Classic ASP = Microsoft/IIS
Everything else = Apache.