DOM Basics
What is the DOM? The Document Object Model is a programming interface that lets JavaScript interact with HTML and CSS on a webpage. When a browser loads a page, it creates a tree-like structure of every element — that tree is the DOM.
The DOM Tree
Every HTML document becomes a tree of nodes. The <html> element is the root, and every tag, attribute, and piece of text is a node within it. JavaScript can read, add, change, or remove any node in this tree.
JavaScript + the DOM
JavaScript uses DOM methods like querySelector, createElement, and addEventListener to select elements, build new content, and respond to user actions — turning static HTML into dynamic, interactive applications.
Why It Matters
Every interactive feature you see on the web — dropdown menus, form validation, live search, infinite scroll — works because JavaScript manipulates the DOM in real time. Mastering the DOM is the gateway to building real web applications.
Prerequisites
Before starting this tutorial series, you should have:
- HTML & CSS basics — understanding of elements, attributes, and styling (HTML tutorials | CSS tutorials)
- JavaScript fundamentals — variables, functions, loops, and conditionals (JS tutorials)
- A modern web browser with developer tools (Chrome, Firefox, or Edge)
Learning Path
Use the DOM to select elements, react to user input, and build more interactive pages.
Introduction to DOM
Learn how the browser turns HTML into a live DOM tree that JavaScript can work with.
Start tutorial →Arrays and Methods
Master JavaScript arrays and useful methods that support DOM-driven data work.
Start tutorial →DOM Manipulation
Select, update, and modify elements dynamically to change what users see on the page.
Start tutorial →Event Handling
Respond to user actions with event listeners, interaction patterns, and form behavior.
Start tutorial →Advanced Events
Work with custom events, focus behavior, throttle, debounce, and more advanced interaction patterns.
Start tutorial →DOM Traversal
Navigate more complex DOM structures by moving between parents, children, and siblings.
Start tutorial →Dynamic Content
Create, insert, clone, and manage new elements dynamically as your UI changes.
Start tutorial →Ready to start? Begin with the Introduction to DOM to learn how the browser turns HTML into a live, programmable structure.