Freestyle
Is any stroke or combination of strokes executed by swimmers. It is often executed as a variation of the "front crawl" stroke, although it does not have to be. Touch may be with any part of the body.
Backstroke
Start is on the back, gripping the block, toes on the wall below water surface. Touch can be with hands, arms, shoulders, or even back of the head. Usually executed as a variation of the "back crawl", although again, it does not have to be. The swimmer must return to a position on the back before feet leave the wall on a push-off.
Breaststroke
Emphasis is on symmetry. Both sides of the body must be a mirror image of each other. The arm pull is made with both arms pulling towards the hips simultaneously from a starting position above the head. The kick is made by moving both legs together simultaneously with the toes pointed out (sometimes referred to as a frog kick). After start and turn, the swimmer is allowed one underwater pull and kick, but the head must break the water surface before the backward motion of the hands reaches the hip line on second arm stroke. Neither dolphin nor flutter kick is allowed. The touch must be at the same time and with both hands at the turn and finish. Shoulders must be level.
Butterfly
Guided by symmetry. Both arms must break and enter the water simultaneously. The legs much move up and down together at all times (sometimes referred to as a dolphin kick). Flutter kicking, scissors kicking, or frog kicking is not allowed. Touch is the same as the breaststroke.
Individual Medley
A race in which a single swimmer swims each of 4 different strokes. The strokes are executed in the order of fly, back, breast and freestyle (freestyle in this case must not be fly, back or breast).
Medley Relay
There are 4 different swimmers swimming each stroke. The strokes are executed in the order of back, breast, fly and free (freestyle in this case must not be back, fly or breast). Touch of the incoming swimmer must be before the outgoing swimmer's toes leave the block.
Freestyle Relay
There are 4 different swimmers each swimming the freestyle. In this case, the freestyle can be any stroke or combination of strokes desired by the swimmers. In most cases, all swimmers swim the "front crawl" during this relay.
Disqualifications
Disqualifications occur when a swimmer:
executes any of the strokes, starts, turns, touches or finishes in a manner inconsistent with the rules for that stroke
false-starts
reports to the block too late.
interferes with a swimmer in another lane.
walks on the floor of the pool.
pulls his or herself along the lane ropes.
fails to finish a race.
jumps into the pool before the preceding swimmers are out of the water (unless a "fly-over start" procedure is being used).
uses abusive language
impedes the progress of the meet.
acts in a manner which the referee deems to be unsafe or un-sportsmanlike.
