The degree to which the elements inside a module belong together represents a critical attribute of software design. It signifies the strength of the relationships between pieces of functionality within a given module. For example, a module exhibiting this property might perform a single, well-defined task, with all of its internal elements contributing directly to that task. Conversely, a module lacking this quality may contain elements that are unrelated or perform disparate functions, hindering maintainability and reusability.
This attribute significantly impacts software quality by enhancing understandability, reducing complexity, and simplifying maintenance. Historically, emphasis on this concept has grown alongside the increasing scale and complexity of software systems. High levels facilitate easier debugging and testing, as well as promote reuse of software components. Consequently, systems designed with this principle in mind tend to be more robust and adaptable to change over time.
