UML style picture showing Jira items relationship

Question

Where do I get an overall UML style picture showing the relations between projets, boards, issues and other Jira's key items.

Jean-Charles Chassot · Answer

Thanks, for your answer.

I finally assembled pieces of info in a very simple and partial diagram:

My goal was to understand how boards, sprints, ... are tied to projects, or not.

Nikola Perisic · Answer

This might be helpful:

Jean-Charles Chassot · Answer

Thanks for your response. 
I feel my question is not clear enough: I'm looking for a representation of Jira principles, not for a feature or an app processing project's specific data.
In fact, a simple documentation picture.