Caffeine is a stimulant and is found naturally in a plethora of plants, including coffee beans, cocoa nuts, and tea leaves. After it has been harvested, caffeine is oftentimes found in coffees, teas, colas, guarana, and other products. 

Caffeine is used for a wide range of purposes, including to enhance mental alertness and acuity. The stimulant can also be used in combination with a painkiller like acetaminophen and aspirin as well as ergotamine to cure migraines. Additionally, caffeine can be utilised to treat the symptoms of gallbladder disease, asthma, attention deficit-hyperactivity disorder (ADHD), weight loss, type 2 diabetes.

Caffeine is referred to as a stimulant as a result of how it works. In short, consumption of caffeine stimulates the user's central nervous system (CNS), muscles, heart, and the bodily regions responsible for controlling blood pressure. In some cases, caffeine is utilised for the purpose of elevating blood pressure, but it does not always have this effect on individuals who use it regularly. In addition to stimulating the user's CNS, caffeine is known to increase urine flow, but again, it does not always have this outcome on individuals who use it consistently. It is often used as a stimulant to aid alertness or used in sports to improve concentration or performance.