Sign system is a key concept in semiotics. It is used to refer to any system of signs and relations between signs. For example, the term language is frequently used as a synonym of a sign system. But, as the term language carries certain connotations of human language, and that is only one type of sign system, the broader term (sign system) is preferred.
Sign system is the broader of both more or less synonymous terms, as it encompasses not only human (spoken) language, but also our body language, tone of voice, and on top of that animal communication, human-machine communication, machine to machine communication, and disease symptoms.
