It's a Music Genre
Reggae is a music genre first developed in Jamaica in the late 1960s While sometimes used in a broader sense to refer to most types of. Jamaican music, the term reggae more properly denotes a particular music style that originated following on the development of ska and rocksteady.
Reggae is most easily recognized by rhythmic accents known as the skank on the off-beat, usually played by guitar, piano, or both. This pattern accents the second and fourth beats in each bar—or the "ands" of each beat, depending on how the music is counted—and combines with the drum's emphasis on beat three to create a unique feel and sense of phrasing. This is in contrast to the way most other popular genres focus on beat one, the "downbeat". The tempo of reggae is usually felt as slower than the popular Jamaican forms ska and rocksteady, which preceded it. It is this slower tempo, the guitar/piano offbeats, the emphasis on the third beat, and the use of syncopated, melodic bass lines that differentiate reggae from other music, although other musical styles have incorporated some of these innovations separately.