What is the difference between 'includes', 'extends' and 'uses'?

Question

In a use case diagram what is the difference between <>, <> and <>? Are

Answer 1

Nice writeup here: http://www.agilemodeling.com/essays/useCaseReuse.htm

Summary from that article:

• An extending use case continues the behavior of a base use case.
• An include dependency is a generalization relationship denoting the inclusion of the behavior described by another use case. The best way to think of an include dependency is that it is the invocation of a use case by another one.
• The inheriting use case would completely replace one or more of the courses of action of the inherited use case.