title: Why do both the abstract class and interface exist in C#?
body: <p>Why do both the abstract class and interface exist in C# if we can achieve the interface feature by making all the members in the class as abstract.</p>
  
  <p>Is it because:</p>
  
  <ol><li>Interface exists to have multiple inheritance</li>
  
  <li>It makes sense to have interface because object's CAN-DO feature should be placed in an interface rather base abstract class.</li></ol>
  
  <p>Please clarify</p>