API (Application Programming Interface)


An API (Application Programming Interface) is a mechanism for making data or capabilities from within an application available to other applications or services.APIs are published by developers who build applications, and consumed by others who want to use that data or service.

Think of publishing an API as a way of advertising what information you have and how people should request it. And consuming an API as asking for information within the parameters you’ve been given.

What’s an example of an API?

Imagine you are a developer building a mapping application and you would like to show users the walkability score of locations as they explore an area.

You might choose to access the U.S. Environmental Protection Agency’s “Walkability Index” API based on census data. Governments, private companies, and other organizations have a number of free and public APIs like this one, in which third-party developers can build with the data offered and integrate into their own projects.

Why is an API used?

An API can be an efficient way to provide third-party developers with access to an organization’s data. When third-party developers experiment with your API, it can result in broader engagement with your services and expanded community reach.

What are the 4 Types of APIs?

  1. Open APIs – Public to all third-party developers
  2. Partner APIs – Accessed only by strategic business partners
  3. Internal APIs – Available to other teams inside an organization
  4. Composite APIs – When multiple APIs are available as a batch that can be requested in a single API call