I need to restore my iphone 5?

My old one broke and i just got the new one in the mail. I already backed up my iphone and i did it again today just to get everything but when i go to restore my phone it asks for a password. I don't remember setting up a password to unlock my restore?
what does it mean and how do i find out what it is?

The password can either be the 4 digit lock code on your iPhone or your apple id password.