Squash is an indoor racquet sport which was, until recently, called "Squash Rackets", a reference to the 'squashable' soft ball used in the game (compared with the harder ball used in its parent game Racquets or Rackets).
The game is played by two players, with 'standard' rackets (or occasionally four players for doubles) in a four-walled court with a small, hollow rubber ball.