A violin is the smallest of the stringed instruments. Other stringed instruments include the viola and the cello. It has four strings, tuned, from low to high, G D A E, each note being a perfect fifth of the one below it. A violin looks like a hollow wooden box with a long neck protruding from one end. The body of the violin is usually made of a couple of different types of wood. The top of the violin, also called the belly, is customarily made of spruce, which is a strong type of softwood. The sides and back are made of maple, which is harder and more durable than spruce. Ebony is most commonly used for the fingerboard, but sometimes ivory is used. Some less expensive models have other types of wood that are merely painted to look like ebony. Traditionally, violin strings were made of gut, but they are usually made of metal now.

The violin is played by pressing the strings against the fingerboard with the left hand while rubbing a bow across the strings with the right hand. The bow is a long wooden rod with stands of horsehair tied to each end. A violin bow looks similar to a bow used to shoot arrows, but is much smaller. Violinists usually play one note on one string at a time, but they can play chords by holding down and bowing more than one string at once. Some pieces of music require the violinist to pluck the strings with the fingers of the right hand rather than bow them, producing a short, staccato sound.

Violins have been in use for many centuries and are still common is contemporary music. The sounds produced by a violin can compliment many other musical instruments and enrich a piece of music.