In programming, what type of abstraction refers to simplifying complex reality while modeling class-based systems?

Data abstraction is the concept that focuses on reducing complexity by hiding the details of how data is structured and managed. In the context of class-based systems, data abstraction allows developers to model real-world entities and their interactions without needing to delve into the intricate details of data handling or implementation specifics. This simplification facilitates a clearer understanding of the system and enhances manageability, as developers interact with objects and classes through well-defined interfaces, focusing on the "what" rather than the "how."

By using data abstraction, programmers can define classes that encapsulate both data and behavior, making it easier to represent complex systems in a simpler form. This allows for easier modification and maintenance of code, as changes to the underlying implementation do not affect how the data is accessed or utilized by other parts of the program.

In contrast, the other forms of abstraction mentioned focus on different aspects of programming. Control abstraction deals with hiding control flow details (like loops and conditionals), procedural abstraction encapsulates routines or procedures, and functional abstraction relates to hiding the implementation details of functions. While all are important in their own right, they do not specifically address the simplification of data representation within class-based systems as effectively as data abstraction does.