What is the difference between extend and include functions in a use case diagram and their uses? - Quora
![Use Case Diagram, UML Diagrams Example: "Include" and "Extend" Use Cases - Visual Paradigm Community Circle Use Case Diagram, UML Diagrams Example: "Include" and "Extend" Use Cases - Visual Paradigm Community Circle](https://circle.visual-paradigm.com/wp-content/uploads/2017/08/Use-Case-Diagram-Include-and-Extend-Use-Cases-1-1280x720.png)
Use Case Diagram, UML Diagrams Example: "Include" and "Extend" Use Cases - Visual Paradigm Community Circle
![UML use case include relationship shows that behavior of the included use case is inserted into the behavior of the including use case. UML use case include relationship shows that behavior of the included use case is inserted into the behavior of the including use case.](https://www.uml-diagrams.org/use-case-diagrams/use-case-include-split.png)
UML use case include relationship shows that behavior of the included use case is inserted into the behavior of the including use case.
![Why using extend and include stereotypes in OOAD projects is wrong? - Jaroslaw Zelinski IT-Consulting Why using extend and include stereotypes in OOAD projects is wrong? - Jaroslaw Zelinski IT-Consulting](https://jaroslawzelinski.biz/wp-content/uploads/2020/08/a-few-citation-uml-specification-a-usecase-is.png)