UML in software engineering knowledge that one has a knowledge point is to include and extend relationships are easily confused, so today is hereby remember the difference between the two at their own convenience after learning and understanding. For example to the following example:
as the picture shows:
> Loan registration information comprises a user login belonging relationship (the include), because the registration information inevitably requires lending to user login, so that a certain relationship with the distinguishing comprising using another embodiment of a use case is bound
> Query and modify library information book information belonging to an expanded relationship (Extend) , because our books every query information if you find book information is wrong then we go to modify book information, if the information we did not query the error would not have to perform every time modify the book information. So distinguish expanded relationship is when we execute a use case is not necessarily going to perform another use case.
