should i create a mysql database as i see (my username)_wrdp1 in cpanel

I have installed 5 wordpress in a go using Cpanel’s fantastico,
and when I enter Mysql Databses, i see a list of :

(myusername)_wrdp1
(myusername)_wrdp2
(myusername)_wrdp3
(myusername)_wrdp4
(myusername)_wrdp5

Do i need to create another mysql database for my wordpress or use the existing one,for eg. using (myusername)_wrdp5 directly instead.

Also, how can i identify which database belongs to each of my wordpress, as they all use the same user name, I cant seem to figure which one.