Abstract Class vs Interface in C#

In C#, abstract classes and interfaces are both used for abstraction and defining contracts, but they have some key differences:

Abstract Class:

• An abstract class can contain both abstract and non-abstract methods.
• Only one abstract class can be inherited by a derived class.
• An abstract class can have fields, properties, constructors, and destructors.
• An abstract class can provide some implementation for its methods.
• Use abstract classes when you want to provide a common base implementation for derived classes.

Interface:

• An interface can only contain method signatures, properties, indexers, and events.
• A class can implement multiple interfaces.
• An interface cannot have any implementation, only method signatures.
• Interfaces are used when you want to define a contract that multiple classes can adhere to.

It's important to choose between abstract classes and interfaces based on the specific design needs of your C# project. Abstract classes are best used when you want to provide a common base implementation, while interfaces are better suited for defining contracts that multiple classes can implement.