Question on C# related to abstract class and interface

Question

What is the difference b/w abstract class and interface and in which scenario each one should be used?

 

 

This question is asked many times in many interviews somehow i was able to answer first part but to satisfy interviewers on second is a bit difficult its a tricky one as well i have searched many times on google but i always get concepts related to both the topics.

 

can anyone please tell me the real scenarios with example where to use both the concepts?

 

Thanks in advance.