Business - a retailer or service company, having an online/electronic system.
Online Payments Page - an online payments system, that allows you to easily build a payments' module into any type of business.
Callback - calling of the service chosen by the business from the banking system to provide updated information on the payment.
System Entering Credentials - a client’s identifier in the banking system (client_id) and a secret key (secret_key), given by the bank to the client upon its successful registration.
Card Number (PAN) - 16 digits given on the front side of the bank card.