authentication question

I installed my certs on my Android phones... it asked for the password for the key, andI was off... just set it to 802.1x TLS and it worked. Now, on my Nook Color, I was able to add my cert, but this time, it only let me choose 802.1x EAP.  That's fine I thought, but then it was looking for a username/password for a user in my MySQL database on the radius server.  That's fine with me too, but I am trying to understand why that one device was the only one that wanted a username/password.