That's right. That's how functors work in category theory.

I've seen a nice article explaining how Haskell types form a category. The objects of the category are types, an arrow a -> b is a function taking argument of type a and returning type b. A Haskell functor is then an endofunctor in this category (i.e. a functor from the category of types to itself). Unfortunately I cannot find the article anymore.