swim styles and stuff related

There are four types of style in swimming those are:

Freestyle: commonly use in long distance competitions it is also the fastest one, the technique consists on circle arms forward, alternating arms, and kick their feet up and down about a foot apart .Although competitors can do whatever they please during the freestyle stroke, it is not common to see someone doing dog paddle, or sidestroke during a race or competition. 

In the first four Olympics, competitions were not held in pools, but, rather, in open water . The 1904 Olympics freestyle race was the only one ever measured at 100 yards, instead of the usual 100 metres. A 100 metre pool was built for the 1908 Olympics and sat in the center of the main stadium's track and field oval.The 1924 Olympics were the first to use the standard 50 meter pool with marked lanes. In the freestyle, swimmers originally dove from the pool walls, but diving blocks were eventually incorporated at the 1936 Olympics.

Breastroke:The style in which the swimmer is on his or her chest and the torso does not rotate. It is the most popular recreational style due to its stability and the ability to keep the head out of the water a large portion of the time. In most swimming classes, beginners learn either the breaststroke or the front crawl first

Breaststroke is the slowest of the four official styles in competitive swimming. The fastest breaststrokers can swim about 1.57 metres per second. Although it is the slowest of the four competitive strokes, it is commonly agreed that it is by far the most difficult.

Backstroke: also sometimes called the back crawl or the upside-down freestyle, This has the advantage of easy breathing, but the disadvantage of swimmers not being able to see where they are going. The maximum swimming speed for backstroke is around 1.89 meter per second. Due to its position on the back, backstroke uses some different muscles in the upper body than other styles.

Butterfly: is a swimming stroke swum on the breast, with both arms moving simultaneously, accompanied by the butterfly kick (also known as the "dolphin kick"). While other styles like the breaststroke, freestyle, or backstroke can be swum adequately by beginners, the butterfly is a more difficult stroke that requires good technique as well as strong muscles, The peak speed of the butterfly is faster than that of the freestyle, due to the synchronous pull/push with both arms. Yet since speed drops significantly during the recovery phase, it is overall slightly slower than freestyle.