# API

A set of rules that lets one program ask another for data or actions.

## What is **API**?

An **API** (application programming interface) is a set of rules that lets one program ask another for data or actions. A weather app calls a weather service's API instead of measuring the weather itself.

Level: Novice · [More Web Development terms at this level](https://www.ask-codey.com/glossary/subjects/web-development/novice)

Updated: September 27, 2026

Source: https://www.ask-codey.com/glossary/api