What does encapsulation achieve in programming?

Encapsulation in programming is a fundamental concept in object-oriented programming (OOP) that involves bundling the data (attributes) and the methods (functions) that operate on that data into a single unit known as a class. One of the primary goals of encapsulation is to restrict direct access to some of the object's components, such as its internal state. This is often achieved through the use of access modifiers, which control the visibility of properties and methods.

By limiting access to certain parts of an object, encapsulation enhances data hiding, which in turn protects the integrity of the data by preventing external entities from making unintended modifications. This restriction allows developers to change the internal implementation of the class without affecting classes that use it, thereby improving maintainability and reducing potential errors.

In contrast, the other options do not accurately reflect the purpose of encapsulation. Allowing complete access to object data would undermine the principle of data hiding. Separating code into different files is related to modular programming rather than encapsulation itself. Automatic code generation pertains to tools or frameworks that assist in writing code but does not connect directly with the core idea of encapsulation.