Integer is a type. List<Integer> is a type. List<T> is a type constructor. In order to get a real type from a type constructor, you need to "pass it type par

Integer is a type. List<Integer> is a type. List<T> is a type constructor. In order to get a real type from a type constructor, you need to "pass it type parameters". In the example above, you need to say that T is Integer.