[Continually Updating A HTML Element In Vanilla JavaScript]

To create DOM nodes, there are two methods:

document.createElement(tag)

Creates a new element node with the given tag:

let div = document.createElement('div');

document.createTextNode(text)

Creates a new text node with the given text:

let textNode = document.createTextNode('Here I am');

Most of the time we need to create element nodes, such as the div for the message.