Simplify the following text for a Grade 12 native English-speaking person.
Original: While all of the former AFL teams along with the NFL 's Cleveland Browns , Pittsburgh Steelers , and Baltimore Colts formed the American Football Conference ( AFC ) , the remaining 13 NFL teams formed the NFC .
Simplified: While all of the former AFL teams along with the NFL 's Cleveland Browns , Pittsburgh Steelers , and Baltimore Colts made up the American Football Conference ( AFC ) , the other 13 NFL teams formed the NFC .