Ping-Pong is the everyday name for the indoor game where two people stand at a table and hit a very light plastic ball to each other with small bats. The ball has to bounce on the table. The more official name is table tennis, and that is what schools and competitions usually print. Ping-Pong began as a trademark and still feels informal and playful, like the sound the ball makes. Same game; the name you choose mostly shows how serious the room is.

桌球（臺灣學校、日常多用這個；中國大陸較常說乒乓球）