Cinnamon is a tree belonging to the Lauraceae family. The bark of the tree is what is used as a spice. True cinnamon or Ceylon cinnamon is native to Sri Lanka. Cassia is a related spice sometimes called cinnamon. Most powdered cinnamon sold in the United States is cassia. It is harder to find true Ceylon cinnamon (Williams Sonoma has it!). Cinnamon is mentioned in Chinese writing as far back as 2800BC. One last fact since we just celebrated (or not) Halloween, in ancient Egypt cinnamon was used in the embalming process.
These are just a few facts about cinnamon but all I think we care about is how wonderful it smells and tastes!