The water is your friend. You don't have to fight with water, just share the same spirit as the water, and it will help you move. ― Aleksandr PopovThere are four basic strokes in swimming: the front crawl, backstroke, breaststroke, and butterfly stroke. Out of these, the front crawl is the most energy-saving technique, provided you do it the right way. Moreover, the relaxation and comfort one gets is just amazing. In the same breath, the most expended swimming style is the freestyle. It is as easy and relaxing to perform compared to the other two. In general, if you may ask, it's hard to say which of the four are better and can be mastered perfectly. They all are different in their own ways, and need enough practice for qualified results.
The front crawl, also called the forward crawl, is the basic swimming technique which is actually regarded as the fastest of all swimming styles. As compared to the backstroke, the front crawl holds a lot of flexibility of the arm and chest when the swimmer is in the water. This stroke has alternating arm strokes, which allows the body to be pushed ahead in a comfortable movement. The technique of performing this front stroke is to stretch both your arms out to the front, and extend both the legs at the back, and then swim.
Freestyle is somewhat like the front crawl, but herein, the body is posed in a manner where the head and the torso are pointed in the downward direction of the swimming pool, and the legs kick constantly up and down to move ahead. Another aspect of freestyle is the coordination of the hands. When one hand is raised and brought back into the water, the other hand should coordinate underneath the water to help move ahead. With all these hand gestures, the head movement is important too. The head must tilt the same side that the body tilts. This is necessary for the swimmer to inhale proper amount of air while swimming.
When you enter the pool, stand still, catch a little momentum to propel your body in the forward direction, and start flinging both arms and legs in the outward direction smoothly. The whole body should form a shape of a 'T'. The arms should bend at the elbows, and the front of the arms must lapse below the water level along with the chin at the surface. By being positioned in this manner, you then have to stretch your arms out in the forward direction, and legs in the backward. This breaststroke technique helps raise the head and torso above the water level, and inhale air at regular intervals.
As striking and difficult this swimming stroke happens to be, it is far more graceful to watch too. The movement of the arms and legs is supposed to be in an upward and downward motion. The arms are brought forward, and then pulled back and brought up once again. Whilst these actions are performed, the legs too are kicked in a powerful motion, something like the dolphin style.
This swimming style is kind of difficult to perform. It is best left for the professional swimmers, or rather those who have perfected the front crawl and freestyle very well. As the name suggests, the swimmer is supposed to lie on his back, and move his arms and legs in a similar style like the front crawl. Although it's an extremely relaxing stroke, almost giving you the effect of being on a beach feeling nice and relaxed, with the backstroke, the navigation of swimming around in the pool gets a bit complex. But yes, there's something to balance it out―the factor of breathing doesn't become a hassle. So all you have to do is lie on your back, try to float your body without sinking in the water, and pedal as if you are riding a bicycle.
On a parting note, remember that practice is the key to success.