An Application Programming Interface (API) is an interface that developers use to access the services of a platform in order to build applications. APIs exist for many different products or services, such as mobile phones, social media networks, and utility software like Dropbox. Typically, an API provides access to data within its ecosystem -- for example, it might provide information about user profiles or project status.
The main topics for API related articles are integration, development, and usage. Common topics include social media APIs, music APIs, documentation tools, and developer resources. The most common topic within the category of APIs is integration with third party systems to extend an app's functionality.