In
programming languages and
type theory, a
product of
types is another, compounded, type in a structure. The "operands" of the product are
types, and the structure of a product type is determined by the fixed order of the operands in the product. An instance of a product type retains the fixed order, but otherwise may contain all possible instances of its
primitive data types. The expression of an instance of a product type will be a
tuple, and is called a "tuple type" of expression. A product of types is a
direct product of two or more types.