Caffeine is a natural stimulant found in various plants and is commonly consumed in beverages and foods. The most popular sources include coffee, tea, and energy drinks. Coffee beans contain the highest caffeine levels, while tea has less but also offers other beneficial compounds. In addition to drinks, caffeine is present in certain foods like chocolate and some medications. Chocolate contains small amounts of caffeine, contributing to its stimulating effects. Many people enjoy these sources for their ability to enhance alertness and reduce fatigue.