What is the difference between a voucher and a coupon?

Coupons provide discounts on specific products, while Clubcard vouchers can be used on any product. Vouchers are applied to your total bill at checkout. To protect your account, Clubcard vouchers can only be redeemed using your own Clubcard. The last four digits of your Clubcard number will be printed on the vouchers so you can track which card the discounts belong to.