The cinnamon stick comes from the interior bark of a tropical evergreen tree. The cinnamon stick is the rolled up bark from the tree. There are two varieties of cinnamon, Cinnamon zeylanicum (Ceylon cinnamon) and Cinnamon cassia (cassia) with the Ceylon cinnamon being "true" cinnamon.
Ceylon cinnamon is softer, easier to grind and has a sweeter but more pungent flavor. You can find this at Mexican stores under the name canela.
Cinnamon is used in many countries. In Mexico it is used a lot in Mexican beverages such as Mexican Chocolate and other dishes like mole sauce.
In India its used in many dishes, including my favorite Indian rice dish called Goan Rice PIlaf. In Europe it is commonly used in breads, cakes and pastries.
Whole cinnamon sticks, no preservatives or additives.
This is a pretty common grocery store item. Mostly you'll find the harder Cassia bark. Look for Ceylon cinnamon at grocery stores that feature Hispanic ingredients. Most of the ground cinnamon you buy is Cassia. You can also purchase Ceylon cinnamon online at Amazon.con