HPP (Hosted Payment Page)
HPP is a hosted payment page located outside the merchant website and operated by third-party providers. It allows customers to pay for goods or services during the checkout process. Store owners can customize the payment page so that it looks like the initial website in terms of the design.
Simply put, with an HPP payment page customer, is automatically redirected to an external payment page so to accomplish the payment.
Besides HPP, there is also an API payment page. Unlike HPP, it does not require redirection to an external link so to accomplish the payment. The entire process happens inside the merchant’s website. API integration increases chances for a repeated purchase and is more preferable for eCommerce.