compiler can decide which form of the object should be invoked during compile time.this type of polymorphism is know as compile time polymorphism

Yes. Inheritance and polymorphism are two different things.

Inheritance is when the attributes and methods of a class are inherited by a deriving class that creates a more specialized type.

Polymorphism is when two methods exist with the same name, differing only in argument types, or in class type. The former type, argument types, is an example of ad-hoc polymorphism that does not even require a class.

polymorphism in coelentrates

Late binding and dynamic binding are related to runtime polymorphism. By contrast, compile time polymorphism is known as static binding. Template functions and classes are examples of static binding because the exact type can be determined at compile time.

Polymorphism means multiple form of a function, variable or object.

In Computer Science, polymorphism is a programming language feature that allows values of different data types to be handles using a common interface.

There are three types : Ad-Hoc Polymosphism, Parametric Polymorphism, Subtype/Inclusion Polymorphism.

Source: Wikipedia.