The Document Object Model (DOM)

The DOM is a tree‑like representation of the HTML document.

• document – entry point.
• document.querySelector() / querySelectorAll() – CSS selector based retrieval.
• document.getElementById(), getElementsByClassName(), getElementsByTagName() – legacy methods.

Node types: Element, Text, Comment, DocumentFragment.

Example: Selecting and modifying an element

const title = document.querySelector('h1');
title.textContent = 'Updated Title';
title.style.color = '#0066cc';