HTML5 Handbook

How HTML Works in a Web Browser

1. Write HTML Code
2. Browser Reads the Code
3. Interpret the Tags
4. Render the Page

XHTML (Extensible HyperText Markup Language)

• XHTML is a stricter and cleaner version of HTML.
• Introduced in 2000, based on XML rules.

Notes:

• Tags must always be properly nested.
• All tags must be closed.
• Tag names/attributes in lowercase.
• Attribute values must be in quotes.

Example:

<p>This is valid in XHTML</p>
<br />
<img src="image.jpg" alt="sample image" />

Comments in HTML (<!-- -->)

• Comments are ignored by the browser.
• Used for documentation, explanations, or disabling code.

Syntax:

<!-- This is a single-line comment -->

<!--
This is a
multi-line comment
-->

Examples:

<p>Hello World!</p>
<!-- This paragraph displays 'Hello World!' -->

<!-- <p>This paragraph is hidden and won’t show on the page</p> -->

<!-- Header Section -->
<h1>Welcome</h1>
<!-- Footer Section -->
<p>Copyright 2025</p>

Output :