Oracle cards are different than tarot cards. Tarot cards have been used since the 15th century, and are in a way, similar to a deck of poker cards. There are suits and specific meanings assigned to each card. Many professional tarot card readers spend months learning how to interpret the cards and how to use the various layouts. I believe that someone who has developed their intuition can get a feel for the energy currently present in someone’s life using the tarot.
Oracle cards aren’t as rigidly defined. Anyone withan intention could create an oracle card deck. The designer of the deck creates the structure and meanings of the cards. There are oracle decks based on angels, saints, unicorns, sacred geometry, animals, and on and on. The idea is that the user of the deck will be drawn to the card that matches their energy or the energy of their question. Most publishing houses require an interpritive booklet for each oracle deck of cards. But a lot of value can be derived from the cards simply by using your intuition.