A symbol is something such as an object, picture, written word, sound, or particular mark that represents something else by association, resemblance, or convention. For example, a red octagon may stand for "STOP". On maps, crossed sabres may indicate a battlefield. Numerals are symbols for numbers.
All language consists of symbols. The word "cat" is not a cat, but represents the idea of a cat.
Psychology has found that people, and even animals, can respond to symbols as if they were the objects they represent. Pavlov's dogs salivated when they heard a sound which they associated with food, even if there was no food. Common psychological symbols include a gun to represent a penis or a tunnel to represent a vagina.[1] See: phallic symbol and yonic symbol.
The psychologist, Carl Jung, who studied archetypes, proposed an alternative definition of symbol, distinguishing it from the term "sign". In Jung's view, a sign stands for something known, as a word stands for its referent. He contrasted this with symbol, which he used to stand for something that is unknown and that cannot be made clear or precise. An example of a symbol in this sense is Christ as a symbol of the archetype called "self".
adapted from: http://en.wikipedia.org/wiki/Symbol
