Swimming is a popular sport both for recreation and competition. There are four strokes (backstroke, breaststroke, butterfly, and freestyle) which are raced at various lengths. There are also three 4-person relays and an event called the individual medley, which combines all four strokes, that are raced. The objective is to be the first person to touch the wall in a race, as well as achieve personal best times in each event.
Races are performed in some combination of one of four strokes: butterfly, backstroke, breaststroke and freestyle. Of these, breaststroke is the earliest to have been practiced. Swimming a certain number of laps of each of the four strokes is known as an individual medley (IM). Modern-day races range from 50 to 1500 meters in distance. Freestyle is raced at distances of 50, 100, 200, 400, 800, and 1,500 meters, and the other three strokes are only raced at distances of 100 and 200 meters. IM is raced at distances of 200 and 400 meters. There are also three relay events, where groups of four swimmers complete a given distance one after the other: there are 4 x 100 and 4 x 200-meter freestyle relays and a 4 x 100 medley relay.
Swimming is part of the Summer Olympics. Men's swimming events have been on the program since the first modern Olympics in 1896 and women's swimming events were added in 1912.