Hello,
Visa Checkout is a digital payment service designed to simplify a customer's checkout experience using a secure, single sign-on across channels and devices using a customer's preferred payment method. When a Visa Checkout button is displayed on a site, visitors can complete their transactions with a user name and password.
Visa Checkout works with an ecommerce site's existing payment ecosystem and does not act as a Payment Gateway, Payment Processor, or Merchant Service Provider. Visa Checkout is not involved in the processing of transactions or funding of Merchant bank accounts.
Visa Checkout can be used by online merchants but there must be an existing, functional Payment Gateway established through a Merchant Service Provider. Funds received via Visa Checkout are deposited into the account established with the Merchant Service Provider along with funds received through the sites standard checkout. Visa Checkout provides customer's with a faster checkout but requires the standard checkout process to function.
Hope this helps !
Thanks,
Jai