What does the "e" parameter located in the event listener do?

First of all, "e" can be the parameter name, but it can be anything you want, like even, myEvent, or event. Second, "e" refers to the event being listened for, so e.target would be how you access the target of that event (Which element receives the event). This is useful if say you have an input field where people can type and submit text. You give each of these texts the same class, and when each is clicked, you want all the "a"s in the text to turn to "b"s (Random example). The only way you would be able to select one of these input fields is by class, and you wouldn't want all the "a"s in all the texts to turn to "b"s when you only clicked the one. This is where e.target comes in. It selects the specific element clicked so only it will change. Hope that helps!