All of these dances are grounded in music. It don't mean a thing if it ain't got that swing. Swing is an authentic American art form. Born in Harlem to its parent the Charleston, the term Swing originally referred to the music.
Swing commonly refers to hanging back, being a little behind the beat.
Some musicians swing tunes, some don't. Same with the dance. You can hang behind the beat and really be there with the music, or you can jump it and race on ahead. We are lucky to have some of the original Savoy dancers around, and teaching, today. Swing dancing emerged in Harlem's Savoy Ballroom, a ballroom that took up a full city block, back in the 1930's, from some teens who wanted to swing out and play with the dance, who wanted to improvise with the dance as their buddies with the instruments were doing on stage.