What is HTML DOM - W3Schools
https://www.w3schools.com/whatis/whatis_htmldom.aspThe HTML DOM (Document Object Model) When a web page is loaded, the browser creates a Document Object Model of the page. The HTML DOM model is constructed as a tree of Objects: The HTML DOM Tree of Objects. Finding HTML Elements. When you want to access HTML elements with JavaScript, you have to find the elements first.
HTML - Wikipedia
https://en.wikipedia.org/wiki/HTMLThe first publicly available description of HTML was a document called "HTML Tags", first mentioned on the Internet by Tim Berners-Lee in late 1991. It describes 18 elements comprising the initial, relatively simple design of HTML.