Contrast the use of an abstract base class against an interface?

Question

Hi,

Contrast the use of an abstract base class against an interface?

please describe..........

Answer 1

In the interface all methods must be abstract, in the abstract class some methods can be concrete. In the interface no accessibility modifiers are allowed, which is ok in abstract classes

Wether to Choose VB.NET/C#.
Both the languages ar using same classes and namespaces. Once it compile and generates MSIL, there is no meaning of which language it was written. If you are Java/C++ programmer better to choose C# for same coding style otherwise you can choose VB.net.