Use Case Diagrams
Use Case Diagrams are a type of behavioral diagram in the Unified Modeling Language (UML) used to visualize the functional requirements of a system by depicting interactions between actors (users or external systems) and use cases (system functionalities). They help in identifying system boundaries, actors, and the relationships between them, serving as a high-level tool for requirements analysis and communication among stakeholders.
Developers should learn and use Use Case Diagrams during the early stages of software development, particularly in requirements gathering and system design phases, to clarify user interactions and system functionalities. They are essential for projects where clear communication with non-technical stakeholders (e.g., clients or business analysts) is needed, such as in agile methodologies or when defining scope for complex systems like enterprise software or web applications.