When you want to make your web page interactive, you need a way to respond to user actions, such as clicks, keyboard input, or mouse movements. The standard method for attaching event handlers to elements in JavaScript is the addEventListener method. This method is preferred over older inline event attributes (like onclick) because it allows you to separate your JavaScript from your HTML, attach multiple handlers to the same event, and remove handlers when needed.

The basic syntax for addEventListener is:

• The first parameter is the event type as a string, such as "click", "mouseover", or "keydown";
• The second parameter is the handler function, which is called when the event occurs;
• The third parameter is optional and can be an object or a boolean. It is usually used for advanced options, such as specifying whether the handler should run during the capturing or bubbling phase, or whether it should only run once.

Using addEventListener is considered best practice because it keeps your code modular and more maintainable. You can attach as many listeners as you want to the same element and event type, and you can remove them later with removeEventListener if needed.