A tennis court is a venue where the sport of tennis is played. It is a firm rectangular surface with a low net stretched across the centre. The same surface can be used to play both doubles and singles matches. A variety of surfaces can be used to create a tennis court, each with its own characteristics which affect the playing style of the game.

The net is 3 feet 6 inches (1.07 metres) high at the posts and 3 feet (0.91 metres) high in the centre. The net posts are 3 feet (0.91 metres) outside the doubles court on each side or, for a singles net, 3 feet (0.91 metres) outside the singles court on each side.

More Info: en.wikipedia.org