Tennis is a sport.
Tennis is a racket sport that can be played individually against a single opponent ( singles ) or between two teams of two players each ( doubles ) . Each player uses a tennis racket that is strung with cord to strike a hollow rubber ball covered with felt over or around a net and into the opponent 's court . Tennis is an Olympic sport and is played at all levels of society and at all ages . A tennis ball is a ball designed for the sport of tennis .