Good swimming technique is a whole-body movement art. With it, you’re the one everyone admires. You make it look so easy. With good technique you move more efficiently, with more speed, less energy, and less risk of injury. Without it, you’re just grinding out the yards or miles, and maybe headed for an injury.
Good swimming technique can be learned, and it can always be improved!
But before you can swim well, you will have to be comfortable and confident in the water. You need to be able to float and breathe with ease, without panic. (See Confidence and Breathing.)
Once you are comfortable in the water, the freestyle stroke is best mastered in small steps, more or less in the order below.
I say more or less, because some steps can be overlapped, and regardless of where you are on the road to mastery, you will need to review and refine all aspects of the stroke, again and again, because freestyle swimming involves a number of trade-offs.
Depending on how fast or far you want to go, you will need to adjust your freestyle stroke to maintain your best possible speed for that time or distance.