What is "Polymorphism" and what are Polymorphism in VB.Net?

Polymorphism is one of the crucial features of OOP. It  means  "one name, multiple forms". It is also called as  Overloading which means the use of same thing for different  purposes. Using Polymorphism we can create as many  functions we want with one function name but with different  argument list. The function performs different operations  based on the argument list in the function call. The exact  function to be invoked will be determined by checking the  type and number of arguments in the function.

Polymorphism  is ability for redefining methods for derived classesin OOPs. its of two types: 1.Compiletime : Method overloading Methods with same name but diff signatures. Example: Public class Calculation public overloads sub Add(x as integer,y as integer)    return x+y End Sub  Public overloads sub Add(x along,y as long, z as long) return x+y+z End sub End class  2.Runtime :Method Overriding  Two or more methods with same name,same signatures but with different implementations.  Example: Public class DrwingObject Public Overridable function Draw() as String return "i am in generic object" End functin End class  Public class Line inherits DrawingObject Public overrides functin Draw() as string return " i am line" End Function End class