Event listeners are a fundamental component of event-driven programming in JavaScript. They allow developers to attach specific functions to particular events on HTML elements, such as clicks, key presses, or mouse movements. When the associated event occurs, the corresponding function, or callback, is executed, managing the interactions within the web application dynamically.
This concept is essential in creating responsive and interactive web applications, as it enables the code to react to user input in real time. By using event listeners, developers can separate the definition of behavior from the elements that trigger those behaviors, making the code more modular and easier to manage.
While callbacks and promises also play significant roles in managing asynchronous operations, event listeners specifically cater to user-initiated events and interactions, which is a core aspect of event-driven programming. Threads, on the other hand, relate more to concurrent execution in programming, which is not the primary focus within the context of JavaScript's event-driven architecture.