Thread:Project:Support desk/What is the difference (and reason) for the "Read" and "Page" tabs?

Is there a particular reason that a wiki page has two tabs that from my perspective appear to perform the same function? One label says "Read" and the other "Page". Both appear to link to the same location or "view" of a page. Is there a interface or historical reason for this seeming duplicity? Note, I'm speaking of the Vector skin.