What is this water sport called?

Swimming is the sport where athletes race through water using their arms and legs together, powered by strokes like freestyle, backstroke, breaststroke, and butterfly. At the Olympics, swimmers push off the wall and race down a long pool as fast as they can, with the fastest swimmer at the finish line winning the race.

Rowing is different — athletes sit in a boat and pull oars, staying on top of the water instead of swimming through it themselves. Surfing means riding ocean waves while standing on a board, which needs real waves, not a calm pool.

Freestyle, the quickest stroke, usually looks like the front crawl, with swimmers reaching one arm over the other while kicking nonstop underwater.