Tarot/Oracle deck difference?

[RunningRiot]

Forgive my ignorance, I've been reading tarot for about five years now and I just thought I'd ask..

What's the difference between an oracle deck and a tarot deck?

[coeur]

"A Tarot deck is at least loosely based on the 78 card structure of 56 minor cards and 22 major cards. An oracle deck is any other deck of cards used for similar purposes to a deck of Tarot cards, and may also be called a divination deck or cartomantic deck." - http://www.aeclectic.net/

[Zephyrstorm]

and an Oracle Deck is built off of some other system. They are largely self-contained, meaning that their symbolism doesn't usually connect them to the Tarot. No Arcana, no suits, just imagery particular to that deck.
Example: Fairy Oracle by Brian Froud - which is based on his personal interactions with the Fey.
Druid Animal Oracle by Phillip Carr-Gomm - based on animals that appear in myths from the British Isles.