Inheritance in Java enables one class to inherit fields and methods from another, promoting code reuse. Using 'class Child extends Parent', the child class inherits all accessible members from the parent. Inheritance models "is-a" relationships: a Dog is-an Animal. The child class can add new members and override parent methods to specialize behavior. Understanding inheritance is fundamental to object-oriented programming and enables building class hierarchies.

Mastering inheritance enables you to create flexible, reusable class hierarchies. Being able to factor common behavior into parent classes prevents code duplication. In professional development, inheritance appears in frameworks, domain models, and polymorphic designs. For example, creating 'Employee' and 'Manager' classes that extend 'Person' captures commonality while enabling specialization. However, prefer composition over inheritance when possible—inheritance creates tight coupling. Use inheritance for true "is-a" relationships and behavioral reuse.

By learning inheritance effectively, you'll understand when it's appropriate versus when composition is better. Knowing that inheritance creates coupling and affects encapsulation helps you use it wisely. This knowledge is fundamental to OOP design. Prerequisites include solid understanding of classes, objects, and polymorphism concepts.