What is the Tarot?
There's 78 cards arranged into two sections, the Major Arcana of what is primary cards, and then a Minor Arcana similar to playing cards but with different suits - pentacles, cups, swords and staffs. Above you see an example from the Major Arcana - The Magician - and you can see the four suits of the Tarot next to the Magician.
While I generally don't do Tarot readings except simple straightforward ones (I personally prefer numerology or rune casting) I tend to use them a lot in my work usually the simplified Rider-Waite deck to give people insights through symbolism. Expect to see them used in my work, including in some of my posts.