multiple blogs

I imagine this is covered in depth somewhere but I have yet to find it, so I apologize if I have missed the obvious. I am trying to decide on a blogging application and WordPress is at the top of the list. However I am unsure it is ideal for what I want to do. From what I have gathered WP only supports one blog. I want to setup multiple blogs on the same server, each on its own sub-domain. Does this mean I will need seperate WP installs for each blog? Will I need seperate mysql databases for each blog?