An API (application programming interface), is a tool used to share content and data between software applications. APIs are used in a variety of contexts, but some examples include embedding content from one website into another, dynamically posting content from one application to display in another application, or extracting data from a database in a more programmatic way than a regular user interface might allow.
Many scholarly publishers, databases, and products offer APIs to allow users with programming skills to more powerfully extract data to serve a variety of research purposes. With an API, users might create programmatic searches of a citation database, extract statistical data, or dynamically query and post blog content. Refer to this stock API guide for more information on how APIs are used in the context of finance and economic research.