Nested Classes

Nested classes in Java are defined within another class and can be static or non-static (inner classes). Inner classes can access both static and non-static members of their enclosing class, while static nested classes can only access static members. Nested classes help in logically grouping related classes, enhancing encapsulation. They can be private, public, protected, or package-private, and serialization of inner classes is often discouraged for compatibility reasons.