It is found in the seeds, fruits, nuts, or leaves of a number of plants native to Africa, East Asia and South America,[13] and helps to protect them against herbivores and from competition by preventing the germination of nearby seeds,[14] as well as encouraging consumption by select animals such as honey bees.[15] The best-known source of caffeine is the coffee bean, the seed of the Coffea plant. People may drink beverages containing caffeine to relieve or prevent drowsiness and to improve cognitive performance. To make these drinks, caffeine is extracted by steeping the plant product in water, a process called infusion.
