Vanilla comes from the pod fruit of a climbing vine in the orchid family. It is the only food coming from this large family. It is native of Central America. The pod, also called a bean, is initially tasteless. The flavor is developed by exposing the pod to to the sun for 10-20 days and then drying it slowly for several months. The process allows vanillin, the principal flavor component, to form.
Vanillin is chemically synthesized from oils of cloves and lignin. Of course, artificial vanillin does not have the complex aroma of the true one.