The substance commonly used in tea is tea leaves, typically derived from the Camellia sinensis plant. This plant species is the source of all traditional teas, including green, black, oolong, and white tea, with variations arising from differences in processing and preparation. Tea leaves contain compounds like catechins, polyphenols, and flavonoids, contributing to their flavor and health benefits. Many people worldwide enjoy tea for its refreshing taste, caffeine content, and cardiovascular benefits. Additionally, flavors can be enhanced with herbs, spices, or fruits, leading to many popular blends and variations globally.