An application programming interface – or API – is what allows different databases, software programs, and applications to communicate with each other effectively.
They allow sites like Kayak.com to aggregate travel deals from around the web, Yelp to populate a map sourced from Google, and your favorite food brands to pull Pinterest recipes onto their website. Each is built to render and communicate specific types of information between two or more different systems.
In the process of ad creation and ad serving, an API takes a call from an ad server, translates the request for whatever ad content is available in a data warehouse, and then expresses it back within the parameters needed to render the ad experience properly.
How the API is built will determine what types of content and creative can be displayed, how quickly it renders, how stable features behave, and much more. The more complex the