An API request is a way for one software application to communicate with another. It allows a program to ask for specific data or services from a server, which can be anything from retrieving user information to sending data for processing. The request is typically made using a set format, often in JSON or XML, and includes details like the type of request (GET, POST, etc.) and any necessary parameters. When the server receives the API request, it processes the information and sends back a response. This response usually contains the requested data or a confirmation of the action taken. APIs are essential for enabling different applications to work together seamlessly, enhancing functionality and user experience.