Sorry, still trying to take advantage of C# and what not.

What does an abstract class do? AFAIK, its like a base a bass class, methods are defined or rather the signature? But there is no actual code and the classes can derrive from this abstract class. Is this correct?

if so, then whats the advantage of this? How would you implement one?


polymorphism - It's been a long time since I heard/used this, I probably do without realizing but can someone tell me what this does and how it benefits us?


protected/internal/virtual/sealed keywords. What do these mean and why are they good/not good and where would you use them? I know using internal classes means that only the classes in the same assembly can access it correct?

Hopefully this should be it and remember, I appreciate each reply. Thanks!