The terms "semantic" and "non-semantic" refer to the way HTML elements are used to convey meaning in a web document.
*Semantic HTML:*
Semantic HTML involves using HTML tags that carry meaningful information about the structure and content of the page. These tags convey the intended meaning of the content they enclose. For example:
html
<header>
<h1>Page Title</h1>
</header>
<article>
<p>Article content goes here.</p>
</article>
<footer>
<p>Copyright © 2023</p>
</footer>
In this example, `<header>`, `<article>`, and `<footer>` are semantic tags that clearly indicate the purpose of the enclosed content.
*Non-Semantic HTML:*
Non-semantic HTML, on the other hand, refers to the use of HTML tags that do not carry specific meaning about the content they enclose. These tags are often used for styling and layout purposes without providing additional context about the content:
html
<div id="header">
<h1>Page Title</h1>
</div>
<div id="main-content">
<p>Article content goes here.</p>
</div>
<div id="footer">
<p>Copyright © 2023</p>
</div>
In this non-semantic example, `<div>` elements are used for layout, but they don't inherently convey the purpose of the enclosed content.
*Key Differences:*
1. *Clarity of Meaning:* Semantic HTML provides a clearer structure and meaning to both developers and browsers, aiding in understanding the content and its context. Non-semantic HTML might be less descriptive about the content's purpose.
2. *Accessibility:* Semantic HTML enhances accessibility by providing a more meaningful structure. Screen readers and other assistive technologies can better interpret and convey the content to users.
3. *SEO:* Search engines may give preference to pages with semantic HTML, as it helps them understand the hierarchy and relevance of content.
4. *Maintainability:* Semantic HTML can improve code maintainability, as the structure and purpose of content are more apparent. Non-semantic HTML may lead to code that is harder to understand and maintain.
In practice, it's recommended to use semantic HTML whenever possible to create more accessible, maintainable, and SEO-friendly web pages. However, a balance might be struck between using semantic and non-semantic elements based on the specific needs of the page and its layout requirements.