Interface

There is no .net 5.0.

The interface is object oriented design and mostly it will not be changed when the framework new version comes.

The interface is pure abstract type in .net. It will have only the structure and there is no implementation. It cannot have any constructors and destructors. It can inherit from another interfaces. This is only way to support multiple inheritance in C#.

It is used to implement the generality or commonality across the system. It will not allow to create the object directly and inherited class should implement all the methods. The public is the default access modifier and it will not allow.

It will allow to use the indexer, property, events and methods.