Shop Pay is a checkout service from Shopify that lets customers save their payment information to speed up the checkout process on participating stores. Customers can store their email address, credit card, shipping, and billing information, which is then encrypted and securely stored on Shopify's PCI compliant servers. When customers return to a store, their saved information can autofill checkout fields. 

Shop Pay also offers chargeback protection from fraud for Shopify merchants. This feature is available for free and helps protect eligible orders against fraudulent and unrecognized chargebacks.