What does a use case diagram visually represent?

A use case diagram visually represents all actors and use cases associated with a system, capturing the interactions between users (or actors) and the functionalities (or use cases) of the system. This type of diagram is useful for understanding the system's requirements from the perspective of the users.

In a use case diagram, "actors" can represent users, external systems, or any entities that interact with the system being modeled. "Use cases" depict specific functionalities or processes that the system must perform in response to the actors' interactions. This visual representation allows stakeholders to grasp the scope of the system, understand who will be using it, and identify the primary objectives or actions the system must support.

The other options are less relevant to the purpose of a use case diagram. For example, while coding components are important for development, they are not depicted in a use case diagram. Similarly, the workflow of system development and regulatory compliance measures involve processes and rules that go beyond what a use case diagram specifically focuses on—the interactions and requirements related to system functionalities. Thus, the use case diagram provides a focused view of actor interactions and system use cases that is critical for requirement analysis.