multiple blogs

When I add my 2nd blog to my hosting, do I add a new database and a new user or just the new user.
I have been reading the codex for 2 days, but am still a bit confused. I know how to do it either way, but I just know which to do.

I don’t get if the database is the same because my hosting is the same or if the database has to do with one blog has one , another blog has one, etc…

Thanks in advance,
Stef

I have cPanel or php I can use so I can go any route, whatever you think is easiest for me to do it thru