What does role binding do?

[wsargent]

I'm a bit confused on Composite Diagrams in UML 2.0.  There's Role Binding, Represents and Occurence, but I don't know which is appropriate and where.  Anyone have any experience here, or can recommend a book to read?

Will.

[Tuser]

Book I'm not sure, but my understanding is below;

Role. I often use Patterns while modelling. You can use the role binding to 'map' a specific class of you, to a 'generalized' class of the pattern.

Occurence. Is sort of opposite of Role. Role assigns a class/component to be part of a collaboration. Assigns a collaboration to be 'part' of a class/component. Again think patterns; if you have defined a Publisher pattern, you might want to show that a class 'EventPublisher' internaly processes according to this pattern. Then you use Occurance.

Represents. Is a mystery to me.