Use Case - Difference between Include and Extend Notation

I see people always struggling with include/exclude notation inside use case diagrams. I think these diagrams could explain it better. use case diagram include…

Structuring Use Cases with Base, Include, and Extend: A Guide for Effective Software Development - Visual Paradigm Guides

Use Case Diagrams and How To Use Them, by Yulia Kosarenko, Business, Architected

Dependencies - Learning UML [Book]

Comparing and Contrasting Use Case Model Elements Part 3 - Business Analyst Articles, Webinars, Templates, Jobs

Use case diagrams are UML diagrams describing units of useful functionality (use cases) performed by a system in collaboration with external users (actors).

UML Use Case Diagram Tutorial Definition, Symbols and More

Use Case Relationships Types.

Use Case Relationships

Include” and “Extend” Use Cases - Visual Paradigm Blog

What is Use Case Relationship? Include, Extend, Generalization - Binary Terms

UML Use Case Diagram Tutorial

UML use case diagrams graphical notation reference - subject, actor, use cases, relationships between them, extend, include.

What is Use Case Relationship? Include, Extend, Generalization - Binary Terms

uml - Use case generalization versus extension - Stack Overflow