Table tennis, also known as ping-pong and whiff-whaff, is a sport in which two or four players hit a lightweight ball, also known as the ping-pong ball, back and forth across a table using small solid rackets. It takes place on a hard table divided by a net. Except for the initial serve, the rules are generally as follows: Players must allow a ball played toward them to bounce once on their side of the table and must return it so that it bounces on the opposite side. A point is scored when a player fails to return the ball within the rules. Play is fast and demands quick reactions. Spinning the ball alters its trajectory and limits an opponents options, giving the hitter a great advantage.