What is the (e) parameter in the EventListener.?? I couldnt get my head around it.

So that means we are adding (e) as an argument , so that we can use it only for the purpose of preventing browser's default behaviour.?

(e) is added as a parameter in the event handler not as an argument, and it can also be used to select elements from the DOM with event bubbling and the DOM traversal concept which is selecting an element based on its relationship to another element within the DOM. For example:

const listItems = document.querySelector('ul');

listItems.addEventListener('click', (e) => {
    if (e.target.tagName == 'BUTTON') {
        let li = e.target.parentNode;
        let ul = li.parentNode;
        ul.removeChild('li');
    }
});

Mike tagged me ....

In an event handler using a conventional function, "this" is set to the event target (same as "e.target" if the parameter is "e"). But the code above uses an arrow function, and arrow functions do not set "this". So in that handler, "this" would just be the window object.