The hostname is, for many of you who will be reading this, the same as your username. This is not always true.
Why is it important? Well, if I want to connect to a box on my network, I use its hostname. For example:
That means I don’t need to know the IP address of the box, I merely need to know the hostname. That, as I said, is usually your username. On the off-chance that it isn’t, it’s easy to find.
And there you go.