The modern orchestral percussion section can vary from a few standard instruments to a whole arsenal, depending on the demands of the music. Percussion instruments made their way into the orchestra relatively late, as references to European military music or, for a more exotic flavor, in imitation of the Ottoman janissary bands which terrorized Europe for centuries. The most standard percussion instruments today are the timpani, the xylophone or marimba, the snare or side drum, the cymbals, the gong or tam-tam and the tambourine.
The tambourine is a small-headed frame drum, consisting of a shallow wooden ring, usually hung with jingles, covered on one side with parchment. It can be played in a variety of ways: the three basic techniques are to 1) strike with the palm, knuckles or closed fist, 2) hold aloft and shake and 3) brush with a moistened thumb for a rolled effect.
The tambourine has a long ancestry and seems to have been found in most parts of the world from ancient times. It became popular in Europe in the Middle Ages, and though usually associated with wandering showmen it rose to the ranks of court ensembles. It was established in the orchestra as need arose for special effects of a Spanish or gypsy character.
Source: The Norton/Grove Concise Encyclopedia of Music, edited by Stanley Sadie. London: Macmillan Press Ltd.,  ISBN 0-333-43236-3