Java IS-A Relationship: How Inheritance Enables Code Reuse Between Classes

In Java's object-oriented programming model, the IS-A relationship — also known as inheritance — allows a child class to acquire the properties and behaviors of a parent class. This is implemented using the extends keyword, enabling child classes to automatically access all accessible members of the parent without rewriting code. Common real-world examples include relationships like SavingsAccount IS-A Account or Manager IS-A Employee, which reflect natural hierarchies in application design. Inheritance improves code reusability, maintainability, and readability by centralizing shared logic in a single parent class rather than duplicating it across multiple child classes. The concept forms part of a broader series on Java OOP principles, with the related HAS-A relationship covering composition and aggregation covered next.