Conservative functor

In category theory, a branch of mathematics, a conservative functor is a functor ${\displaystyle F:C\to D}$ such that for any morphism f in C, F(f) being an isomorphism implies that f is an isomorphism.

The forgetful functors in algebra, such as from Grp to Set, are conservative. More generally, every monadic functor is conservative.¹ In contrast, the forgetful functor from Top to Set is not conservative because not every continuous bijection is a homeomorphism.

Every faithful functor from a balanced category is conservative.²