A voucher or coupon is a promotional tool used by businesses to encourage customers to make purchases. It typically offers a discount or a special deal, such as a percentage off the total price or a fixed amount off a specific product. Vouchers can be found in various forms, including printed paper, digital codes, or mobile app offers. Customers can redeem these vouchers at the point of sale, either online or in-store, to receive the advertised benefits. They are often used in marketing campaigns to attract new customers or retain existing ones, making them a popular strategy in the retail industry.