multisite and php problem

hi,

Once i created local host with xamp,i created a database for my first site.And got log on to wordpress.
Then i make a small site…

After that i made wordpress “multisite” to create multiple sites at once in same wordpress and added a new site.everything was cool.I can create any number of sites… But in the php myadmin page ,the database remains same on the name i created for my previous site.So is it like both sites have one database or what?

Im soo confused…Sometimes i feel like im lost…maybe most of the time..Or is it only in the startup trouble im getting …. 😉