Type system
The type system of a language interprets values in memory, including how to store them, based on a language's set of rules. A type system uses rules and constraints for verifying the association of data types (e.g., integer, float, string) with various language constructs (e.g., variables, expressions, functions). Its purpose is to reduce errors (type safety) from mismatches and rule violations (type checking) that govern how values are interpreted and operated on, in different parts of a program. Variables, expressions, functions, and modules may be assigned to types.