Definition from Wiktionary, the free dictionary
direct product (plural direct products)
- (set theory) The set of functions from the indexing set of an indexed family of sets to the union of the family, whose values at any given index lie in the set indexed thereby.
- For example, if A and B are sets, their direct product is the set of pairs (a,b) with a in A and b in B.
- (mathematics) The generalization of direct product (1) to arbitrary categories.
in set theory — see Cartesian product
in category theory — see categorical product