What does encapsulation refer to in object-oriented programming?

Encapsulation in object-oriented programming is fundamentally about bundling or combining data (attributes) and methods (functions) that operate on that data into a single unit called a class. This design paradigm allows for a clear structure where the properties of an object and the behaviors associated with those properties are encapsulated within the object itself. This means that users of the class can interact with the object without needing to understand the low-level details of how the data is stored or manipulated; they simply work with the methods provided by the class.

By organizing data and methods together, encapsulation enhances modularity, making the code more maintainable and easier to understand. It also supports the principles of information hiding and abstraction, which help in reducing complexity in large software systems. Hence, the focus on the combination of data and methods accurately describes the essence of encapsulation in object-oriented programming.