-Inheritance is a way to form new classes (instances of which are called objects) using classes that have already been defined.
-Inheritance is employed to help reuse existing code with little or no modification.
-The new classes, known as Sub-class or derived class, inherit attributes and behavior of the pre-existing classes, which are referred to as Super-class or Base class.
It is a kind of topic which is not explainable without examples.
please go through this MSDN article..
http://msdn.microsoft.com/en-us/library/27db6csx(v=vs.90).aspx[
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