Direct product vs categorical product Is what we call direct products (of groups, vector spaces, modules,...) actually the same as what we call categorical products? Why the word "direct"?
no, direct sums are biproducts (coproducts and products). But what one usually writes as infinite "direct sum" is an infinite coproduct.
no, direct sums are biproducts (coproducts and products). But what one usually writes as infinite "direct sum" is an infinite coproduct.