AutoMapper is a popular object-to-object mapping library that can be used to map objects belonging to dissimilar types. As an example, you might often need to map the DTOs (Data Transfer Objects) in your application to the model objects.
AutoMapper is an object-to-object mapper, which allows you to solve issues with mapping of the same properties in one object of one type to another object of another type.
It is explained beautifully in belowlink,,https://dotnettutorials.net/lesson/automapper-in-c-sharp/