API

An API, or Application Programming Interface, is a programmed set of functions and procedures that enable computers to interface with other computers. Within the payments ecosystem, APIs ensure that all involved parties – processors, banks, eCommerce stores, and so on – are speaking the same “language” behind the scenes.

APIs allow user input through a familiar format, such as an online shopping cart. The API sends that input to a server, which translates the data to a programming language any receiving computer can understand. The receiver performs the necessary actions, and the results are sent back to the user in a readable way.

This enables users to send or accept payments through apps or online shopping platforms. Payment APIs are typically customizable, allowing merchants to configure their payment processing based on the businesses' particular requirements.