In music, the term swing has two main uses. Colloquially, it is used to describe the propulsive quality or "feel" of a rhythm, especially when the music prompts a visceral response such as foot-tapping or head-nodding (see pulse). This sense can also be called "groove".
The term swing feel, as well as swung note(s) and swung rhythm, is also used more specifically to refer to a technique (most commonly associated with jazz but also used in other genres) that involves alternately lengthening and shortening the first and second consecutive notes in the two part pulse-divisions in a beat.