Cointreau is a French orange-flavored liqueur, specifically a type of triple sec, known for its clear, crystalline appearance and balanced, intense flavor of sweet and bitter oranges. It's made from a blend of sweet and bitter orange peels, along with sugar and alcohol derived from sugar beets. Cointreau is versatile, enjoyed on its own as an aperitif or digestif, and is a key ingredient in many classic cocktails like the margarita, sidecar, and cosmopolitan.