The kola nut actually got its name thanks to the caffeine content it possesses (cola=caffeine). It is native to the tropical rain forested parts of Africa, and is often included in beverages that contain caffeine as it also acts as a natural flavoring agent. Kola nuts are obtained from a few related plants all belonging to the genus cola.
Not surprisingly, it has been consumed natively by people residing in those areas as it can help to stimulate energy, and is even used in religious ceremonies, presented to chiefs of tribes or visiting guests.
In the Western world, you are likely to see kola nut, sometimes just regarded as “cola” or “kola” mentioned on the labels of many energy boosting drinks and supplements.