A symbol is a mark, sign, or word that indicates, signifies, or is understood as representing an idea, object, or relationship. Symbols allow people to go beyond what is known or seen by creating linkages between otherwise very different concepts and experiences. All communication (and data processing) is achieved through the use of symbols. Symbols take the form of words, sounds, gestures, ideas, or visual images and are used to convey other ideas and beliefs. For example, a red octagon is a common symbol for "STOP"; on maps, blue lines often represent rivers; and a red rose often symbolizes love and compassion. Numerals are symbols for numbers; letters of an alphabet may be symbols for certain phonemes; and personal names are symbols representing individuals. The variable 'x', in a mathematical equation, may symbolize the position of a particle in space. The academic study of symbols is semiotics. In cartography, an organized collection of symbols forms a legend for a map. Etymology The word symbol derives from the late Middle French masculine noun symbole, which appeared around 1380 in a theological sense signifying a formula used in the Roman Catholic Church as a sort of synonym for 'the credo'; by extension in the early Renaissance it came to mean 'a maxim' or 'the external sign of a sacrament'; these meanings were lost in secular contexts. It was during the Renaissance in the mid-16th century that the word took on the meaning that is dominant today, that of 'a natural fact or object evoking by its form or its nature an association of ideas with something abstract or absent'; this appears, for example, in François Rabelais, Le Quart Livre, in 1552. This French word derives from Latin, where both the masculine noun symbolus and the neuter noun symbolum refer to "a mark or sign as a means of recognition." The Latin word derives from the Greek σύμβολον symbolon, from a verb meaning 'throw together, put together, compare,' alluding to the Classical practice of breaking a piece of ceramic in two and giving one half to the person who would receive a future message, and one half to the person who would send it: when the two fit perfectly together, the receiver could be sure that the messenger bearing it did indeed also carry a genuine message from the intended person. A literary or artistic symbol as an "outward sign" of something else