# Introducing the DOM

Introducing the DOM: Introducing the DOM: an overview, Locating DOM elements.

Updated: November 3, 2026

1. [Introducing the DOM: an overview](https://www.ask-codey.com/lessons/introducing-the-dom-an-overview) (Novice): When the browser loads a page, it turns the HTML into the DOM, a tree of objects with one for each element, and JavaScript reads and changes the page through that tree.
2. [Locating DOM elements](https://www.ask-codey.com/lessons/introducing-the-dom-locating-dom-elements) (Apprentice): Most searches start at the document, the whole page, where getElementById finds an element by its id, querySelector finds the first match for a CSS selector, and querySelectorAll finds every match.

Source: https://www.ask-codey.com/courses/csharp-full-stack-bootcamp/topics/csharp-introducing-the-dom