Document Structure
<html>: Root element.<head>: Metadata, links, scripts.<body>: Visible content.<meta>
charset: Character encoding.viewport: Responsive settings.description: SEO-friendly page description.author: Specifies the author of the page.robots: Controls search engine behavior.
Text & Formatting
<h1> - <h6>: Headings.<p>: Paragraph.<strong> / <em>: Bold/italic with meaning.<br>: Line break.<blockquote>: Quoted text.<mark>: Highlighted text.<abbr>: Abbreviations (tooltip on hover).<a>: Hyperlink.
href: URL.target="_blank": Opens in a new tab.
Lists
<ul>: Unordered list (bullets).<ol>: Ordered list (numbers).<li>: List item.
Media
<img>: Displays an image (alt for accessibility).