Competitive swimming is a popular sport that is included in big events such as the Olympic Games and the Commonwealth Games. Swimming has 4 main strokes with events that are 50 Meter (m), 100m and 200m races with the exception of Freestyle which also has races that are 400m, 800m and 1500m. There is also the Individual Medley (IM) which includes 100 (short course only) 200m and 400m races. An IM includes all 4 strokes, for example a 200m IM would include 50m butterfly, 50m backstroke, 50m breaststroke and 50m freestyle. There is also relay events, which consist of 4 swimmers. Relays can either be 4x50 (200m) or 4x100 (400m) Freestyle or Medley. However a Medley is a different order to an IM. The first leg is backstroke, breaststroke, butterfly and freestyle.
Swim Seasons are the differences between a 25m pool and a 50m pool. The short course (25m) season lasts from approximately May to September and long course (50m) lasts from October to April. In the most big swimming events including the Olympics, the 50m pool is used.