UML use case diagrams can be used to visualize a project before it takes place or as documentation for a project afterward. Nevertheless, the overall goal of UML use case diagrams is to allow teams to visualize how a project is or will be working, and they can be used in any field, not just software engineering. As shown in the UML Use Case below, use-case diagrams model a system's behavior and help capture the system's requirements. It should be noted here that the use-case diagrams describe a system's high-level functions and scope. These diagrams also identify the interactions between the system and its actors.