A boy band is loosely defined as a vocal group consisting of young male singers, usually in their teenage years or in their twenties at the time of formation. Generally, boy bands perform love songs marketed towards girls and young women. Many boy bands dance as well as sing, usually giving highly choreographed performances. South Korean boy bands usually also have designated rappers.

A girl group is a music act featuring several female singers who generally harmonize together. The term "girl group" is also used in a narrower sense in the United States to denote the wave of American female pop music singing groups, many of whom were influenced by doo-wop and which flourished in the late 1950s and early 1960s between the decline of early rock and roll and start of the British Invasion. All-female bands, in which members also play instruments, are usually considered a separate phenomenon. These groups are sometimes called "girl bands" to differentiate, although this terminology is not universally followed.