Some TFS Links

I'm not clear on the difference between a TFS Issue and a User Story. Is there some sort of loose hierarchy between TFS work items? Work Items and Workflow (Agile)

http://msdn.microsoft.com/en-us/library/dd997897.aspx

Artifacts (Agile)

http://msdn.microsoft.com/en-us/library/dd997580.aspx

MSF for Agile Software Development v5.0

http://msdn.microsoft.com/en-us/library/dd380647.aspx

You can only delete workitems with the tfs cmd tools "destroywitd"

http://msdn.microsoft.com/en-us/library/dd236914.aspx

If you want to convert, why not link :) i.e. issue really needs to be a story issue745 ----links to----> newUserStory787