What is the process by which unnecessary details are hidden to focus on high-level functions?

The process of hiding unnecessary details to emphasize high-level functions is known as abstraction. This concept allows developers to simplify complex systems by providing a clear interface that focuses on essential characteristics without exposing the intricacies involved. By abstracting the details, it enables easier understanding and interaction with the code, making it more manageable and enhancing code reusability.

In programming, abstraction often involves defining classes or functions that encapsulate what the components do rather than how they do it. This separation ensures that users of the component can utilize it effectively without needing to understand the underlying complexity. For example, when using a car, a driver does not need to know how the engine works (the intricate details); they simply need to know how to operate the steering wheel and pedals (the high-level functions).

The other options involve different concepts: encapsulation relates to bundling the data with the methods that operate on it; decomposition is about breaking down a problem into smaller, more manageable parts; and refactoring focuses on restructuring existing code to improve its readability and structure without changing its external behavior. These concepts, while valuable, do not specifically address the process of focusing on high-level functions through the hiding of details.