Coupons are promotional tools that businesses use to offer discounts or incentives to customers. Here are some key definitions related to coupons:

1. Coupon: A voucher or code that provides a discount or special offer on a product or service. Coupons can be physical (paper-based) or digital.

2. Discount Coupon: A type of coupon that reduces the price of an item by a specific amount or percentage when applied at purchase.

3. Promo Code: A digital coupon in the form of a code, usually entered during online checkout to apply a discount.

4. Manufacturer Coupon: A coupon issued by the manufacturer of a product, which can be redeemed at retailers selling the product.

5. Store Coupon: A coupon provided by a specific store or retailer, valid only at that location or chain.

6. Buy One Get One (BOGO): A type of coupon that allows customers to buy one item and get another for free or at a discount.

7. Rebate: A post-purchase coupon that offers a refund or partial refund after the purchase is made, usually by submitting proof of purchase.

8. Digital Coupon: A coupon that exists in electronic form, often found on websites, apps, or sent via email.

9. Stacking Coupons: The process of using more than one coupon on a single purchase to maximize discounts, typically combining store and manufacturer coupons.

10. Expiration Date: The date after which a coupon is no longer valid for use.

11. Coupon Code: A string of letters, numbers, or both that shoppers can enter at checkout to receive a discount.

12. Mobile Coupon: A coupon that can be used by displaying it on a mobile device, often through an app or text message.

13. In-Store Coupon: A coupon that can be used in physical retail locations as opposed to online.

14. Loyalty Coupon: A coupon offered to repeat customers as a reward for their loyalty, often through a rewards program.

These terms cover the basic types of coupons and how they are typically used in both physical and online retail contexts.