![Use case diagrams are UML diagrams describing units of useful functionality (use cases) performed by a system in collaboration with external users (actors). Use case diagrams are UML diagrams describing units of useful functionality (use cases) performed by a system in collaboration with external users (actors).](https://www.uml-diagrams.org/use-case-diagrams/use-case-diagram-elements.png)
Use case diagrams are UML diagrams describing units of useful functionality (use cases) performed by a system in collaboration with external users (actors).
![Use case diagrams are UML diagrams describing units of useful functionality (use cases) performed by a system in collaboration with external users (actors). Use case diagrams are UML diagrams describing units of useful functionality (use cases) performed by a system in collaboration with external users (actors).](https://www.uml-diagrams.org/use-case-diagrams/business-use-case-diagram-elements.png)
Use case diagrams are UML diagrams describing units of useful functionality (use cases) performed by a system in collaboration with external users (actors).
![Use Case Diagram Example - This diagram illustrates the basic principles of a use case diagram: Actors, System b… | Employee management, Business analysis, Use case Use Case Diagram Example - This diagram illustrates the basic principles of a use case diagram: Actors, System b… | Employee management, Business analysis, Use case](https://i.pinimg.com/originals/38/55/7b/38557b51c5ed9b1dc6655344c66afeea.png)