Irish dancing or Irish dance is a group of traditional dance forms originating in Ireland which can broadly be divided into social dances and performance dances. Irish social dancing can be divided further into céilí and set dancing. Irish set dances are quadrilles, danced by four couples arranged in a square, while céilí dances are danced by varied formations (céilí) of two to sixteen people. In addition to their formation, there are significant stylistic differences between these two forms of social dance. Irish social dance is a living tradition, and variations in particular dances are found across the Irish dancing community; in some places, dances are deliberately modified and new dances are choreographed.