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.
String instrument
A single string at a certain tension and length only produces one note. To produce multiple notes, string instruments use one of two methods. One is to add enough strings to cover the required range of different notes (e.g., as with the piano, which has sets of 88 strings to enable the performer to play 88 different notes). The other is to provide a way to "stop" the strings along their length to shorten the part that vibrates, which is the method used in guitar and violin family instruments to produce different notes from the same string. The piano and harp represent the first method, where each note on the instrument has its own string or course of multiple strings tuned to the same note. (Many notes on a piano are strung with a "choir" of three strings tuned alike, to increase the volume.) A guitar represents the second method—the player's fingers push the string against the fingerboard so that the string is pressed firmly against a metal fret. Pressing the string against a fret while plucking or strumming it shortens the vibrating part and thus produces a different note.