Uncover This Tech Term: Application Programming Interface for Large Language Models
Chae Ri Park, Hwon Heo, Chong Hyun Suh, Woo Hyun Shim · Korean Journal of Radiology · 2025
What is an API?An application programming interface (API) is a set of rules that allows different software applications to communicate easily with each other.When one program needs to obtain data or use certain functionalities from another program, it simply makes a "request" according to the predefined format of the API.The second program then processes this request and provides the desired "response" or "service."A key benefit here is that the requesting application does not need to understand exactly how the other system internally operates [1,2].To illustrate this intuitively, we consider the analogy of dining at a restaurant.A customer (the user) selects dishes from a menu (available services or functions) and communicates their request to a waiter (the API).The waiter then delivers this request to a specific station or section in the kitchen (representing the endpoint, exact location, or resource where the request is processed by