Fruit or fruits

[Alex1]

Hello
I've been taught that there is no such thing as fruits, that the plural form for fruit is fruit. Yet I see "fruits" all over. Is it correct to use this form and if so, on what conditions?

Thanks in advance.

[gorilla]

As my teacher said: 'fruits' = 'fruit types' (like apple, grape, banana)

[Alex1]

Thanks a lot.