a three turn is a figure skating element which envolves both change of edge and direction, for example when a skater executes a forward outside three turn, he or she will start gliding on 1 foot on an outside edge then quickly turn backwards into a back inside edge. there are 8 three turns in all, one for each possible combination of direction (foreward or backward) skating foot (left or right) and edge (outside or inside).
the turn is named for the tracing that it makes on the ice, each edge makes a curve, and the change of edge in between them makes a point, it looks roughly like the numeral three.