Adding an additional blog. Possible?

I have just installed WordPress on my Linux server. I am hosting two websites, mine and that of a friend. Now that I have a blog, my friend wants to know if he can have one too, but I do not know whether that is possible and I do not see anything specific about this in the documentation.

If this is possible, please respond, and point out the appropriate documentation, if you can.

Hopefully this is the correct forum to post this. If not, please move it to a more appropriate.

Thanks,

Bob