Strings (tennis)
In tennis, the strings are the part of a tennis racquet which make contact with the ball. The strings form a woven network inside the head (or "hoop") of the racquet. Strings have been made with a variety of materials and possess varying properties that have been measured, such as dynamic stiffness, tension retention, thickness (gauge), string texture (shape of the string), and rebound efficiency.
Tennis court
The dimensions of a tennis court are defined and regulated by the International Tennis Federation (ITF) governing body and are written down in the annual 'Rules of Tennis' document. The court is long. Its width is for singles matches and for doubles matches. The service line is from the net. Additional clear space around the court is needed in order for players to reach overrun balls for a total of wide and long. A net is stretched across the full width of the court, parallel with the baselines, dividing it into two equal ends. The net is high at the posts, and high in the center. The net posts are outside the doubles court on each side or, for a singles net, outside the singles court on each side.