A language is a system of symbols, generally known as lexemes and the rules by which they are manipulated. The word language is also used to refer to the whole phenomenon of language, i.e., the common properties of languages. Language is commonly used for communication, though it has other uses.
Language is a natural phenomenon, and language learning is common in childhood. In their usual form, human languages use patterns of sound or gesture for the symbols in order to communicate with others through the senses. Though there are thousands of human languages, they all share a number of properties from which there are no known deviations. There is no defined line between a language and a dialect, but it is often said that a language is a dialect with an army and a navy.
Humans have also constructed other languages, including Esperanto and Klingon, programming languages, and various mathematical formalisms. These languages are not necessarily restricted to the properties shared by natural human languages.
Some of the areas of the brain involved in language processing: Broca's area, Wernicke's area, Supramarginal gyrus, Angular gyrus, Primary Auditory Cortex.