types of strokes [3]
Four basic categories are recognized by the International Amateur Swimming Federation (FINA): the breaststroke, the butterfly, the backstroke and freestyle (the crawl).
butterfly stroke 
Stroke on the stomach in which the two arms are thrust simultaneously toward the front and then brought backward.
butterfly turn 
Movement for making a half turn; the swimmer touches the wall with both hands, pivots, then pushes from the wall with the feet.
butterfly kick 
Vertical simultaneous movement of the legs that completes an undulation started by the upper body; the legs always stay together.