types of strokes 
Four basic categories are recognized by the International Amateur Swimming Federation (FINA): the breaststroke, the butterfly, the backstroke and freestyle (the crawl).
front crawl stroke
Stroke performed on the stomach in which the arms alternate in moving toward the front; it is very fast and is usually used in freestyle races.
Dive enabling the swimmer to thrust the body into the water; the swimmer pushes off with the legs, extends the body and enters the water head first.
Expulsion of air; the swimmer breathes out when the face is underwater.
Wall that the swimmer must touch before turning around; during the turn, the athlete pushes from the wall with the feet.
Movement in which the outstretched legs alternate in beating up and down.
Action of drawing air into the lungs; to breathe in, the swimmer turns the head slightly, without lifting it.
Movement for making a turn: the swimmer curls downward, pivots, then pushes from the wall with the feet.