Convert your AOL username to an Apple ID

Hi,

I use my AOL email as my apple id. I read the following in a discussion on this subject,

"You only need to convert your Apple ID if it is your AOL screen name, not your AOL email address. If your sign in information includes @aol.com or similar, you do not need to convert."

Ok ... I'm lost!!! What's the difference between my AOL email address and my AOL login? Help! 😕 Thanks!