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Object-Oriented Programming (OOP) in Java is a programming paradigm based on the concept of "objects," which can contain both data and methods. It simplifies software development and maintenance through several key concepts:

1.Inheritance: Inheritance allows a new class (subclass or child class) to inherit properties and behaviors from an existing class (superclass or parent class). This promotes code reusability and establishes an "is-a" relationship between classes.
2.Polymorphism: Polymorphism means "many forms." In Java, it allows objects of different classes to be treated as objects of a common superclass. This can be achieved through method overriding (runtime polymorphism) and method overloading (compile-time polymorphism).
3.Abstraction: Abstraction focuses on showing only essential information to the user and hiding the complex implementation details. In Java, this is achieved using abstract classes and interfaces.
4.Encapsulation: Encapsulation is the bundling of data (attributes) and methods that operate on the data within a single unit (class). It also involves restricting direct access to some of an object's components, typically through access modifiers like private, and providing public methods (getters and setters) to interact with the data. This protects data integrity and improves maintainability.