An API (Application Programming Interface) is a set of rules that lets software programs communicate with each other. When you check the weather on your phone, the app sends a request to a weather API, which responds with data (temperature, forecast) that the app displays. Most modern APIs are REST APIs that use HTTP requests: GET (read data), POST (create data), PUT (update data), DELETE (remove data). The data is almost always formatted as JSON. APIs are the backbone of modern software — every app, website, and service uses dozens of APIs behind the scenes.
glossary2 min read
What is an API?
APIs let software programs talk to each other. Learn how REST APIs work in plain English.
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