Object-oriented programming (OOP) is a programming paradigm that uses objects as the fundamental building blocks of software applications. In OOP, an object is a self-contained entity that contains both data and behavior. The data represents the state of the object, while the behavior represents the actions that the object can perform.
OOP works by defining classes, which are like blueprints or templates for creating objects. A class defines the data and behavior that are common to all objects of that type. Once a class is defined, objects can be created from it, and each object has its own unique data and behavior.
The key concepts of OOP include encapsulation, inheritance, and polymorphism. Encapsulation refers to the idea of hiding the internal details of an object from the outside world, so that the object can only be accessed through a set of well-defined methods. Inheritance allows one class to inherit the data and behavior of another class, making it easier to reuse code. Polymorphism allows objects of different classes to be treated as if they were of the same class, which makes it possible to write more flexible and reusable code.
OOP is widely used in modern software development, and many programming languages support it, including Java, C++, Python, and Ruby.