instruction: What is table tennis and why is it popular
context: Table tennis, also known as ping-pong and whiff-whaff, is a racket sport derived from tennis but distinguished by its playing surface being atop a stationary table, rather than the court on which players stand. Either individually or in teams of two, players take alternating turns returning a light, hollow ball over the table's net onto the opposing half of the court using small rackets until they fail to do so, which results in a point for the opponent. Play is fast, requiring quick reaction and constant attention, and is characterized by an emphasis on spin relative to other ball sports, which can heavily affect the ball's trajectory.
  Owed to its small minimum playing area, its ability to be played indoors in all climates, and relative accessibility of equipment, table tennis is enjoyed worldwide not just as a competitive sport, but as a common recreational pastime among players of all levels and ages.
response: Table tennis is a sport that plays a ball on a table with rackets. Its rule has evolved over the years, like the material of the racket and balls, size of the balls. Like tennis, it can also play simple or double games. It is popular because it doesn't require a big area, and normally people can play it even at an older age.