Use Case Diagram
A Use Case Diagram is a visual representation in Unified Modeling Language (UML) that depicts the interactions between actors (users or external systems) and a system to achieve specific goals. It illustrates the functional requirements of a system by showing use cases (actions or services) and their relationships, helping to define system scope and user interactions. This diagram is commonly used in software engineering and business analysis to capture high-level system behavior.
Developers should learn Use Case Diagrams during the requirements gathering and design phases of software development to clarify system functionality and user roles. They are particularly useful for identifying key features, communicating with stakeholders, and ensuring alignment between technical and business teams. Use cases help in planning test scenarios and documenting system requirements before implementation.