Java holds the distinction of being one of the most universally embraced programming languages, powering a multitude of applications ranging from web development to enterprise software. Consequently, it is paramount for developers to gain a comprehensive understanding of the language's concepts and features. Nested classes stand as one such feature that we'll explore in this article. Our discussion will encompass the essence of nested classes, their various classifications, and their practical applications in Java. Additionally, we will shed light on the benefits of enrolling in online Java course training with H2KInfosys. Unpacking Nested Classes: Nested classes in Java, are classes defined within another class, effectively residing within the encompassing or outer class.