Uml System Diagram. Analysis and design of the static view of an application. An actor is a person organization or external system that plays a role in one or more interactions with your system.
Behavioral diagrams on the other. The registrar is logged into the system. Sequence diagram of a hospital management system.
A unified modeling language uml diagram depicts a system and how users or other systems interact with yoursa system could be a website an app or maybe a business process.
Use case diagrams depict. Basic course of action. They include the class component and or object diagrams. Erd diagrams are commonly used in conjunction with a data flow diagram to display the contents of a data store.