For example, you can call addEventListener('click', handler) on an element multiple times, with different functions specified in the second argument: This is impossible with event handler properties because any subsequent attempts to set the property will overwrite earlier ones: You might also see a pattern like this in your code: The earliest method of registering event handlers found on the Web involved event handler HTML attributes (or inline event handlers) like the one shown above the attribute value is literally the JavaScript code you want to run when the event occurs. The same result can be achieved with a function expression: The code above uses a function expression to store the handler function in a variable const greeting. To learn more, see our tips on writing great answers. The above example invokes a function defined inside a