The systematic classification of plant extracts is fundamental to phytochemistry and natural product research. It is primarily based on the chemical nature of the extracted compounds, which dictates their properties and applications. Major classes include alkaloids, like caffeine from coffee; phenolics, such as the anthocyanins in blueberries; terpenoids, found in essential oils like menthol from mint; and polysaccharides, including pectin from citrus fruits. This chemical taxonomy enables targeted extraction methods, ensures reproducibility, and guides the selection of extracts for specific uses in pharmaceuticals, nutraceuticals, and cosmetics. A clear classification system is therefore indispensable for advancing plant-based science and innovation.