Coumarin (2H-chromen-2-one) is the parent compound of the coumarin class of benzopyrone derivatives, occurring naturally in plants such as tonka beans, sweet clover, and cinnamon. It appears as colorless crystalline solid with a characteristic sweet, hay-like odor. Coumarin and its derivatives display diverse bioactivities including anticoagulant, anti-inflammatory, antimicrobial, and antioxidant effects. It serves as a key precursor in pharmaceutical synthesis and perfumery. While used historically as a flavoring agent, regulatory restrictions now limit food use due to hepatotoxicity concerns. The compound absorbs UV light and exhibits fluorescence in certain derivatives, making it useful in analytical chemistry and laser dyes.