Nested Class can be used whenever you want to create more than once instance of the class or whenever you want to make that type more available. Nested Class increases the encapsulations as well as it will lead to more readable and maintainable code.
Read moreWhat is the use of nested class?
As mentioned in the section Nested Classes, nested classes enable you to logically group classes that are only used in one place, increase the use of encapsulation, and create more readable and maintainable code .
Read more