Triple sec is an orange liqueur distilled three times at 20-40°. The fruit peels macerate for several months in vats filled with alcohol to obtain an infusion which will be distilled. It can be sweetened with sugar or honey (100g/L min).
Curaçao, originally made by the ductch, is generally considered a triple sec, it takes its name from the island of Curaçao, an island in the Netherlands Antilles, which produces small bitter oranges.