Sym in MatLab and others similar function of sym

The short name of 'sym' comes from the word 'symbolic'. Symbolic is the adjective of a 'symbol' word. Symbolic means serving as a symbol or acting as a symbol. Now, what is sym in MatLab programming language?
Sym is the process of creating symbols in a MatLab program in order to express variables, expressions, equations, functions, and matrices in an oriented way.