Application Programming Interface — a way for software systems to communicate with each other and exchange data programmatically.
An API defines the methods and data formats that one system uses to request data from another. REST APIs are the most common type for web services. Many open data portals provide APIs that allow developers to query datasets programmatically rather than downloading files.
APIs enable real-time data access, automated data pipelines, and integration between systems. An API key is often required to authenticate requests.