A duty-free shop is a retail outlet that sells goods exempt from the payment of certain local or national taxes and duties. These shops are typically located at international airports, seaports, and border crossings, allowing travelers to purchase items without the added costs of taxes. Common products include alcohol, tobacco, perfumes, cosmetics, and luxury goods. To shop at a duty-free store, customers usually need to show a valid passport and proof of international travel. The items purchased are meant for personal use and must be declared upon entering the destination country, as there are limits on the quantity of goods one can bring back without incurring taxes.