Discussion on: NodeJS and DOM API

You may be confused because you are writing it in JavaScript but JavaScript doesn't have that.

Neophytes tend to get confused because of the lack of distinction between JavaScript language features and execution environments that execute JavaScript.

The MDN (Mozilla Developer Network) is one of the best JavaScript resources but is dedicated largely to browser based JavaScript.

Example: JavaScript data types and data structures

Look at the page's breadcrumbs:

"References > JavaScript > JavaScript data types and data structures"

i.e. this is a JavaScript (programming language) topic

Another example: EventTarget.addEventListener()

Breadcrumbs:
"References > Web APIs > EventTarget > EventTarget.addEventListener()"

Not a JavaScript topic but it's about the browser based Web API that can be accessed with JavaScript on a browser.

Finally: Express web framework (Node.js/JavaScript)

Breadcrumbs:
"Guides > Server-side website programming > Express web framework (Node.js/JavaScript)"

Not a reference but a tutorial about Server-side website programming with Node.js. And because it's server-side there'll be templates to generate HTML (later forms) but nothing about the DOM (This approach would be considered dynamic server rendering).

Most of the Node.js specific information can be found on the Node.js API site and Knowledge Base and while JavaScript is everywhere JavaScript, the programming language isn't really discussed here.

Other things like Express or React (Preact; JSX isn't part of JavaScript) have their own sites.