What is the difference between extend and include functions in a use case diagram and their uses? - Quora
![Use Case Diagram, UML Diagrams Example: Website (structuring use cases with extend and include use case) - Visual Paradigm Community Circle Use Case Diagram, UML Diagrams Example: Website (structuring use cases with extend and include use case) - Visual Paradigm Community Circle](https://circle.visual-paradigm.com/wp-content/uploads/2017/08/Use-Case-Diagram-Website-_-Structuring-use-cases-with-extend-and-include-use-case-3-1280x720.png)
Use Case Diagram, UML Diagrams Example: Website (structuring use cases with extend and include use case) - 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.
![Use Case Diagram, UML Diagrams Example: Website (structuring use cases with extend and include use case) - Visual Paradigm Community Circle Use Case Diagram, UML Diagrams Example: Website (structuring use cases with extend and include use case) - Visual Paradigm Community Circle](https://circle.visual-paradigm.com/wp-content/uploads/2017/08/Use-Case-Diagram-Website-_-Structuring-use-cases-with-extend-and-include-use-case-2.png)
Use Case Diagram, UML Diagrams Example: Website (structuring use cases with extend and include use case) - Visual Paradigm Community Circle
![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)
Why using extend and include stereotypes in OOAD projects is wrong? - Jaroslaw Zelinski IT-Consulting
![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
![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)