OOPS, or Object-Oriented Programming, is a programming paradigm that uses objects and classes for organizing code. The four pillars of OOP are: Encapsulation: Definition: Encapsulation is the bundling of data (attributes) and the methods (functions) that operate on the data into a single unit, known as a class. It restricts access to some of the object's components, preventing the direct modification of data from outside the object. Purpose: Encapsulation helps in hiding the internal details of an object and protects its integrity. It also promotes modularity and code organization. Abstraction: Definition: Abstraction is the process of simplifying complex systems by modeling classes based on the essential properties and behaviors an object should have, while ignoring unnecessary details. Purpose: Abstraction allows programmers to focus on the relevant features of an object, hiding the unnecessary complexity. It facilitates code reusability and the creation of abstract classes and interfaces. Inheritance: Definition: Inheritance is a mechanism by which a new class, called a derived or child class, can inherit properties and behaviors from an existing class, known as a base or parent class. This promotes code reuse and establishes a relationship between the two classes. Purpose: Inheritance helps in creating a hierarchy of classes, allowing the child class to inherit and extend the features of the parent class. It facilitates the creation of a more generalized and specialized class structure. Polymorphism: Definition: Polymorphism means "many forms." In OOP, polymorphism allows objects of different classes to be treated as objects of a common base class. It enables a single interface to represent different types of objects, and it can take different forms, such as method overloading and method overriding. Purpose: Polymorphism enhances flexibility and extensibility in code. It simplifies code maintenance and promotes the use of a common interface for interacting with objects of various types.