Handlers are specialized software components that manage events or actions in a program. They listen for specific triggers, such as user inputs or system notifications, and execute predefined responses. This allows for efficient processing of tasks without requiring constant monitoring by the main program. In many programming languages, handlers are often associated with event-driven programming. For example, in a web application, a click handler might be used to respond when a user clicks a button, executing a function that updates the display or sends data to a server. This modular approach enhances code organization and responsiveness.