Events

Distances:

50 metres - 2 lengths in a 25 metre, 1 length in a 50 metre pool

200 metres - 8 lengths in a 25 metre, 4 lengths in a 50 metre pool

400 metres - 16 lengths in a 25 metre, 8 lengths in a 50 metre pool

500 metres - 20 lengths in a 25 metre, 10 lengths in a 50 metre pool

800 metres - 32 lengths in a 25 metre, 16 lengths in a 50 metre pool

1000 metres - 40 lengths in a 25 metre, 20 lengths in a 50 metre pool

1600 metres - 64 lengths in a 25 metre, 32 lengths in a 50 metre pool

These are the recognised distances for competitive swimming. Most commonly, different strokes constitute different comment events. For example, freestylers commonly swim most events - from 50 to 1600 metres - while butterflyers commonly swim shorter distances - mostly 50 to 400 metres.

IM:

The Individual Medley is a race that combines all the strokes swum in the order of Backstroke, Breaststroke, Butterfly, Freestyle. This order is used during swimming meets as backstroke is started in water and so is swim first. During practices, or at any other time, however, the order is Butterfly, Backstroke, Breaststroke, Freestyle. This event is both an individual race - as the name constitues - but can also be a relay, meaning that it would be a team of 4 and each person swims one of the strokes.