What does encapsulation refer to in object-oriented programming?

Encapsulation in object-oriented programming (OOP) refers to the practice of restricting access to certain components of an object. This principle is fundamental to OOP because it helps in hiding the internal state and behavior of an object, only exposing a controlled interface for interaction. By using encapsulation, you can prevent external code from directly accessing and modifying the internal data of an object, thereby maintaining the integrity of the object and its data.

This is typically achieved through access modifiers such as private, protected, and public, which control how and where the attributes and methods of a class can be accessed. For instance, when a class has private properties, those properties can only be accessed through public methods (often called getters and setters), allowing for validation, modification, or processing of data before it is retrieved or altered.

This practice not only enhances security and reliability but also promotes modularity and maintainability within code, enabling easier debugging and updates.