The butterfly stroke is a swimming technique characterized by a simultaneous arm movement and a unique body undulation. Swimmers begin with their arms extended in front, then pull them down and back in a sweeping motion while lifting their chest and legs. This stroke requires strong coordination and rhythm to maintain speed and efficiency in the water. In addition to the arm movements, the butterfly stroke involves a distinctive kick known as the dolphin kick. Swimmers keep their legs together and perform a fluid, wave-like motion from the hips. Mastering this stroke can be challenging, but it is one of the four competitive swimming styles used in events.