Writing is a medium of communication that represents language through the inscription of signs and symbols. In most languages, writing is a complement to speech or spoken language. Within a language system, writing relies on many of the same structures as speech, such as vocabulary, grammar and semantics, with the added dependency of a system of signs or symbols, usually in the form of a formal alphabet. The result of writing is generally called text, and the recipient of text is called a reader. Motivations for writing include publication, storytelling, correspondence and diary. Writing has been instrumental in keeping history, dissemination of knowledge through the media and the formation of legal systems.