The term "Backend" refers to the part of a software application or website that users do not see. It is responsible for managing the server, database, and application logic. The backend processes requests from the frontend, which is the visible part of the application, and sends back the necessary data. Backend development involves using programming languages like Python, Java, or Ruby to create the server-side logic. It also includes working with databases such as MySQL or MongoDB to store and retrieve data efficiently. Overall, the backend ensures that everything runs smoothly behind the scenes.