Classes containing at least one abstract method are called abstract classes, and must include the abstract keyword before the class keyword. If you forget the abstract keyword when defining the class, you get an error from the C# compiler:
Abstract classes use the abstract keyword. They do not have a method body; a semicolon follows the parameter list instead.
Abstract methods are also, by definition, virtual methods, and must be overridden by derived classes using the override keyword:
The C# compiler doesn't allow you to create objects from abstract classes. If you try to create an object from an abstract class
Interfaces describe a group of related functionalities that can belong to any classor struct.
Interfaces can consist of methods, properties, events, indexers, or any combination of those four member type
Interfaces members are automatically public.
When a class or struct is said to inherit an interface, it means that the class or struct provides an implementation for all of the members defined by the interface.
A class or struct can inherit more than one interface.
When a class or struct inherits an interface, it inherits only the method names and signatures, because the interface itself contains no implementations.
I hope it will help you
Mark as answer if it helps you
Saranya Boopathi, if this helps please login to Mark As Answer. | Alert Moderator