Encapsulation is a fundamental concept in object-oriented programming that involves bundling the data (attributes) and methods (functions) that operate on the data into a single unit, known as a class. This approach helps to restrict direct access to some of an object's components, which is a means of preventing unintended interference and misuse of the data. By using encapsulation, developers can create a clear separation between an object's internal state and its external interface. This not only enhances security but also improves code maintainability and flexibility, allowing changes to be made to the internal workings of a class without affecting other parts of the program.