How do you explain a tennis match to a kid?

Recent, I was teaching a student who is 8 years old and just starting to compete at the game of tennis. She asked me, "what is the purpose of tennis". I pondered about the answer. Obviously if you are playing a match, the purpose is to win the match. And to win a match, you must string together enough points to win two sets. And to win points,mother best way is to hit the ball away from your opponent or force your opponents to make errors.

But then I wondered. Are there other purpose to tennis? What about mastering strokes? What about getting fitter to play it well? And how we decide what the purpose of tennis is and which purposes to prioritize? Readers, I would love your thoughts.