There are two basic types of cinnamon. Ceylon or true cinnamon and Cassia which is not actually real cinnamon but comes from a related tree. The bark of the cassia tree is thicker and the flavor is hotter and less complex.
Ceylon cinnamon is typically made from the inner bark of the real cinnamon tree. The bark is thinner, the flavor lighter with less heat, and more complex with perhaps some fruity and/or floral notes.
Most of what is sold today as cinnamon is Cassia and not Ceylon. The classic "red hot" flavor is cassia and in particular that of cassia with Chinese origins. Yes, the flavor of cinnamon varies depending on origin just like wine -- or my favorite -- cocoa / chocolate.
The typical flavor that we are used to from companies such as Schilling stems from cassia from Indonesia. Vietnamese cinnamon is particularly strong having about twice the amount of cinnamon oil in it as regular varieties. China as I mentioned earlier grows a cassia that has the classic "red-hot" flavor.
Ceylon cinnamon is used in Scandinavian cooking as well as traditional Mexican cooking. Ceylon incidentally is the former name of Sri Lanka.
Some manufacturers use a blend. CinnaBon from what I understand uses a blend for their cinnamon that they sell at a premium at their stores. This is also the reason why they are the only one with their "kind" of cinnamon that and it is a trademarked name so nobody else could "have it" even if they had the same blend.
Here is a picture that I took of a Ceylon cinnamon tree that I found on one of my cocoa bean hunting travels.
There is both natural and artificial cinnamon oils that you may purchase. When I was in high school, I'd use natural cinnamon oil to make cinnamon toothpicks which were all the rage back then. (I was known for having the hottest and so it made good for some good bargaining at school.)
As a side note, while in Jr. High, our English teacher stepped out of class and so I handed out cinnamon toothpicks to everyone in the class. They were of course, against the rules and when the teacher came back the room reeked of cinnamon. Our teacher Mr. Faubus said: "I smell cinnamon ... who has cinnamon toothpicks?" He then called on this kid in the back row, and said : "Mark, go to the office for the rest of the period." Mark went and we all looked at each other with cinnamon toothpicks hanging out of our mouths....
Back to point: The artificial cinnamon oil is well ... artificial. I'd guess it is used for Potpourris and similar I've never looked into it particularly far since there is obviously something much better on the market.
Hope this helps,
-Art
