The term polymorphism is very common topic in oops.
"Poly" means many and "morphism" means form. This a Greek word.
It means polymorphism is ability to work at many form at a time.
A code that can re-use by multiple time is known as polymorphism.
There is two type of polymorphism ...
1) Compile time Polymorphism(Static Binding/ Method Overloading).
2)- Run-time Polymorphism (Dinamic Binding, Method Overriding).