I read the readme file of this script, postlister.

It tells me to enter the database name and username and password.
and also the server form whic the host is on and they recommened localhost.

whats al this? do i need to create a database? if so, how? my host says there's a folder whereby my database files are to be placed into..i ahev no idea whats this at all.
can someone kindly explain to me pls?