Event is that we make things interactive. When we are interacting with a web page, we may click on a button, hover over a picture, drag or drop something, or press the Enter Key. All of those are events and happen all the time. The process of event is that we select an element and then add an event listener to the element we selected. To add a listener, we use a method called addEventListener . element.addEventListener(type, functionToCall); There are two arguments for the addEventListner. Type : the type of event we want to listen for such as "click" FunctionToCall : the function is the code that we want to run when that event happens In our daily life, there are three most popular event types we use all the time: click, mouseover, and mouseout. Click We always like to click the "start" button to start a game or start shopping. How could we do that event in JavaScript? I open the DOM page, and I want the page to pop up an alert message wh...