What Is an API? Definition & Guide

An API (Application Programming Interface) is an interface that lets two software programs communicate and exchange data by following precise rules, without either one knowing how the other works inside.

How an API works

An API works like a waiter in a restaurant: your software makes a request (the order), the API takes it to another system and brings back the response (the dish), without you ever entering the kitchen. When a site shows a map, weather or a payment, it is calling another service's API. The data usually travels in JSON format.

What APIs are for

• Integrations: they connect your site to couriers, payment gateways, management systems or an ERP.
• Separation: they let a front-end talk to the back-end and the database.
• Content: they are the foundation of a headless CMS.

APIs and security

APIs must be protected with access keys, authentication and rate limits, because they expose data to the outside. A well-designed integration is reliable and secure: in our web development we build and connect custom APIs.

Related terms: Back-end & Front-endHeadless CMSDatabase

Frequently asked questions