The tarot is a pack of playing cards that was used from the mid-15th century in various parts all across Europe to play card games. However from the late 18th century until the present time the tarot is more commonly used by mystics and occultists in efforts at prophecy or as a map of mental and spiritual pathways. Don’t scoff at such notions. I have personally known people, quite rational and successful, that routinely go to a reader for guidance. Now whether you think it is merely entertainment or take it quite seriously is up to you, but you can’t deny it is any less theoretical or possible than the legion or religious books you find on the shelves at your local bookstore.