Difference between Tarot and Orcale Decks

What are the difference of using a Tarot Deck and Orcale deck?

There are numerous threadas ont this if you type "difference tarot oracle" in the search field.

A very comprehensive and good one is
http://www.tarotforum.net/showthread.php?t=58648

It also shwos that there are varying opinions about this seemingly simple question

Thanks Aulruna!