Net sports

Net sport may refer to any of several sports where a net is a standard part of the game. The term usually applies to sports where the net separates the opponents. The basic goal in these sports is to hit the ball or bird over the net back to the opponent. Players score points whenever the opponent fails to return the ball or bird back over the net. The criteria on what is considered a valid return varies between each sport (such as the number of times the ball may be touched or bounced on a player's side before it must go back over the net).

Net sports usually include:

Although basketball, hockey, water polo and other sports have netting around the goal area designed to more clearly indicate when goals are scored, they are not usually considered "net sports". Similarly, lacrosse sticks have a loose netting that is used to catch and fling the ball, but again lacrosse is not usually considered a "net sport".

The Los Angeles Daily Times reports: "Net sports are unique in that the equipment is light, portable and affordable, and partners and opponents are easy to find. The sports are easy to learn, and the social aspect of the game[s] appeals to those who find the health club to be an isolationist palace of mirrors."

The three "favorite" net sports (tennis, badminton, and volleyball) usually involve arching of the back when serving or spiking/smashing the ball or bird.

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Wikipedia