In REST architecture, a representation refers to the data in the format used to transmit and exchange information between the client and server. It serves as a standardized way for the client and server to understand and work with the data being sent or received.

Let's consider a scenario where a user requests information about a flight using my API. The API will respond with a representation of the flight data in JSON format. This representation will contain various attributes, such as the flight number, departure and arrival times, airport details, and more.