Object-oriented programming (OOP) is a programming paradigm that revolves around the concept of objects. It is a way of structuring software programs to closely mimic the real world. The background of OOP can be traced back to the 1960s with the development of Simula, a programming language designed for creating simulations. From there, OOP gained popularity with the introduction of languages like Smalltalk, C++, and Java. The key principles of OOP include encapsulation, inheritance, and polymorphism. These principles allow for the creation of modular, reusable, and scalable code. OOP has become an integral part of modern software development, as it promotes code organization, reusability, and maintainability. Understanding the background of OOP is crucial for developers to leverage its power and build efficient and robust software systems.