A payment gateway is a hardware and software system that automates the acceptance of payments online, including crypto payments, linking the buyer, the seller, and the payment system.

SEPA is a single euro payments area that simplifies cashless transfers between banks of member countries under common rules and standards.

A payment service provider (Payment Service Provider, PSP) is a service that allows payments to be accepted and sent by various methods, combining many payment methods in a single interface for businesses and users.

A QR code is a two-dimensional graphic image that encodes data and is read by a camera; in cryptocurrencies it is used to quickly transmit addresses and payment details.

A merchant is a trade or service business that accepts payment cards and, in many cases, cryptocurrencies. The term comes from the English word merchant.