Application Programming Interface (API)

An Application Programming Interface (API) is a code library assembled by a web service company to enable third-party applications to communicate with a web service platform. Though an API is an interface, it is an interface for computer-to-computer communication and therefore is not presented to the human user in the way that you normally think of when you hear the word “interface.” Instead, a company may build a front end display on top of their API to support human use. Every time you use a web service like Facebook or Twitter, you are interacting with an API through the front-end tools developed for human users. However, as APIs are for computer-to-computer communication, there are more direct ways to interact with APIs as well using programming languages.