Backstreet Boys is a duo.
The Backstreet Boys ( often abbreviated as BSB ) are an American vocal group , formed in Orlando , Florida in 1993 . The group consists of AJ McLean , Howie D. , Nick Carter , Kevin Richardson , and Brian Littrell . The group then released two albums as a quartet : Unbreakable ( 2007 ) and This Is Us ( 2009 ) . The Backstreet Boys have sold over 130 million records worldwide , making them the best-selling boy band in history , and one of the world 's best-selling music artists .