An Application Programming Interface (API) is a set of rules and protocols that allows different software applications to communicate and share data with each other. Think of an API as a waiter in a restaurant—you tell the waiter what you want, the waiter communicates with the kitchen, and brings back your food without you needing to know how the kitchen works. APIs enable the connected digital services we use daily: when a weather app shows forecasts, it uses an API to request data from weather services. Government open data initiatives often provide APIs so developers can create applications using public information.