polymorphism vs overriding in java
Overriding is when you call a method on an object and the method in the subclass with the same signature as the one in the superclass is called.
Polymorphism is where you are not sure of the objects type at runtime and the most specific method is called. Therefore the behaviour of the method called may differ, depending on the objects type at runtime.
Overriding is a type of polymorphism along with overloading and dynamic (late) binding.