"Turn, Turn, Turn" is a song written by Pete Seeger and popularized circa 1965 in a 45 rpm single by The Byrds. It is essentially an admonishing plea for world peace framed in a reading from the Old Testament's Ecclesiastes 3: 1-8 ("To everything there is a season and a time for every purpose under Heaven...").
Generally, a turn can be a change of the direction of a movement or a change in orientation, and it is often also used in a metaphorical sense, contrary to straight.
In geometry, a turn is a unit of angular measure equal to 360°.
In music, a turn is a sequence of several notes next to each other in the scale which is often abbreviated symbolically.
I finally came to understand that the difference lies in the action of the hips: a turn is made by a twisting motion of the pelvis, the largest, heaviest, and most central bone in the body.
This propeller-like motion causes the rest of the body to turn, the body pivots on the ball of one foot, and increased momentum is achieved by a whipping or slicing motion of the opposite arm and/or leg.
Because confident turns are the hallmark of an accomplished dancer (not to mention one of the five basic body moves that make up dance, according to dance master and researcher Rudolf Laban).