The
butterfly (colloquially among swimmers known as
fly) is a
swimming stroke swum on the breast, with both arms moving simultaneously, accompanied by the butterfly kick (also known as the "
dolphin kick"). While other styles like the
breaststroke,
front crawl, or
backstroke can be swum adequately by beginners, the butterfly is a more difficult stroke that requires good technique as well as strong muscles. It is the newest
swimming style swum in competition, first swum in 1933 and originating out of breaststroke.