Swimming is movement when moving in water. Swimming is usually done without artificial supplies. This activity can be used for recreation and sport. Swimming is used when moving from one place to another in water, fishing, bathing, or doing water sports.

Swimming for recreational purposes and competitions is carried out in the pool. Humans also swim in rivers, lakes and seas as a form of recreation. Swimming sports make the body healthy because almost all of the body's muscles are used when swimming.

In recreational swimming, people swim in the breaststroke, backstroke, freestyle and butterfly stroke. The swimming styles that are contested in swimming competitions are butterfly, backstroke, breaststroke and freestyle. In the freestyle number swimming competition, swimmers can use a variety of swimming styles, except for breaststroke, backstroke and butterfly stroke. Unlike breaststroke, backstroke and butterfly stroke, the International Federation does not regulate the techniques used in freestyle swimming numbers.

However, almost all swimmers swim in the pulley style, so the front crawl is used almost universally by swimmers in the freestyle swimming numbers.