The tournaments are played on a squared flat surface, called a tennis court. The measurements of a tennis court are described and monitored by the ITF and the court is long, wide. Its width is for singles matches and for doubles matches. Tennis is played on a variety of court types and each type has its own aspects that control how the sport is played. There are four main types of courts based on what's used to build the court surface, clay, hard, grass and carpet courts with the ITF rating five different speed ratings from slow to fast.