Controllers are devices or software that manage and direct the operation of other devices or systems. For example, in video games, a game controller allows players to interact with the game by sending commands, such as moving characters or using items. Similarly, in electronics, a microcontroller can control various functions in gadgets, like turning lights on and off. In the world of computing, controllers can also refer to software components that handle data flow between different parts of a system. For instance, in web development, a controller in the Model-View-Controller (MVC) framework processes user input and updates the display accordingly, ensuring a smooth user experience.