Semantic HTML

This article explains semantic HTML.

Compare HTML4 with HTML5 and explain the semantic tags used in HTML5.

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HTML5 Semantic Tags

Semantic tags, such as the <header> and <main> tags, are tags that carry meaning, introduced in HTML5. Before that, in HTML4, the <div> tag was mainly used.

Below is an example of HTML5 created using semantic tags.

 1<!DOCTYPE html>
 2<html lang="en">
 3<head>
 4    <meta charset="UTF-8">
 5    <meta name="viewport" content="width=device-width, initial-scale=1.0">
 6    <title>HTML5 Example</title>
 7</head>
 8<body>
 9    <!-- Header -->
10    <header>
11        <h1>Welcome to My Website</h1>
12    </header>
13
14    <!-- Navigation menu -->
15    <nav>
16        <ul>
17            <li><a href="#">Home</a></li>
18            <li><a href="#">About</a></li>
19            <li><a href="#">Contact</a></li>
20        </ul>
21    </nav>
22
23    <!-- Main content -->
24    <main>
25        <h2>About Us</h2>
26        <p>This is a simple website created using HTML5 tags.</p>
27    </main>
28
29    <!-- Footer -->
30    <footer>
31        <p>&copy; 2024 My Website</p>
32    </footer>
33</body>
34</html>

Below is an example of HTML4 created using <div> tags.

 1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 2<html lang="en">
 3<head>
 4    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 5    <title>HTML4 Example</title>
 6</head>
 7<body>
 8    <!-- Header -->
 9    <div id="header">
10        <h1>Welcome to My Website</h1>
11    </div>
12
13    <!-- Navigation menu -->
14    <div id="nav">
15        <ul>
16            <li><a href="#">Home</a></li>
17            <li><a href="#">About</a></li>
18            <li><a href="#">Contact</a></li>
19        </ul>
20    </div>
21
22    <!-- Main content -->
23    <div id="main">
24        <h2>About Us</h2>
25        <p>This is a simple website created using HTML4 structure.</p>
26    </div>
27
28    <!-- Footer -->
29    <div id="footer">
30        <p>&copy; 2024 My Website</p>
31    </div>
32</body>
33</html>

An example of a blog post written using semantic tags.

There are also other semantic tags like <article> and <section>. As an example, we will write a blog post using semantic tags.

 1<!DOCTYPE html>
 2<html lang="en">
 3<head>
 4    <meta charset="UTF-8">
 5    <meta name="viewport" content="width=device-width, initial-scale=1.0">
 6    <title>My Blog</title>
 7    <link rel="stylesheet" href="theme-blog.css">
 8</head>
 9<body>
10    <!-- Website Header -->
11    <header>
12        <h1>My Blog</h1>
13        <p>Sharing knowledge and ideas</p>
14    </header>
15
16    <!-- Navigation Menu -->
17    <nav>
18        <ul>
19            <li><a href="index.html">Home</a></li>
20            <li><a href="about.html">About</a></li>
21            <li><a href="contact.html">Contact</a></li>
22        </ul>
23    </nav>
24
25    <!-- Main Content -->
26    <main>
27        <!-- Blog Article -->
28        <article>
29            <header>
30                <h2>Understanding Semantic HTML</h2>
31                <p>Posted on <time datetime="2024-09-08">September 8, 2024</time> by <a href="author.html">John Doe</a></p>
32            </header>
33
34            <section>
35                <h3>What is Semantic HTML?</h3>
36                <p>Semantic HTML refers to the use of HTML5 elements that clearly describe their meaning in a human- and machine-readable way.</p>
37            </section>
38
39            <section>
40                <h3>Why is Semantic HTML Important?</h3>
41                <p>Using semantic tags helps improve accessibility, search engine optimization (SEO), and the overall structure of the web page. It allows search engines to better understand the content, and assistive technologies to accurately convey information to users.</p>
42            </section>
43
44            <footer>
45                <p>Tags: <a href="#">HTML</a>, <a href="#">Web Development</a>, <a href="#">Accessibility</a></p>
46            </footer>
47        </article>
48
49        <!-- Related Articles (Sidebar) -->
50        <aside>
51            <h3>Related Articles</h3>
52            <ul>
53                <li><a href="#">The Benefits of Using Semantic HTML</a></li>
54                <li><a href="#">Improving SEO with Semantic Markup</a></li>
55                <li><a href="#">Accessible Web Design: Best Practices</a></li>
56            </ul>
57        </aside>
58    </main>
59
60    <!-- Website Footer -->
61    <footer>
62        <p>&copy; 2024 My Blog. All rights reserved.</p>
63        <p><a href="privacy.html">Privacy Policy</a> | <a href="terms.html">Terms of Service</a></p>
64    </footer>
65</body>
66</html>
  • <header>: <header> tag is used for the page's overall header as well as for each article's header. It includes the website title, article title, publication date, and author information.

  • <nav>: <nav> tag represents the site's navigation menu, containing links like Home, About, and Contact.

  • <main>: <main> tag represents the main content of the page, including blog articles and related content.

  • <article>: <article> tag is a semantic tag that wraps the blog article itself, indicating that the article is independent content.

  • <section>: <section> tag represents each section within the article.

  • <aside>: <aside> tag represents supplementary information related to the main content, such as 'Related Articles'.

  • <footer>: <footer> tag is used for the overall footer of the page and to display tags for the article.

Using semantic tags like this makes the structure of the document clearer. For example, the <body> tag consists of <header>, <nav>, <main>, and <footer> tags. Additionally, the <main> tag consists of <article> and <aside> tags.

In this example, the <article> tag also consists of semantic tags.

Example of Applying CSS

Now, let's apply CSS to the HTML of the blog article. CSS will be explained in a separate video.

  1/* Reset */
  2* {
  3    margin: 0;
  4    padding: 0;
  5    box-sizing: border-box;
  6}
  7
  8/* Body styles */
  9body {
 10    font-family: Arial, sans-serif;
 11    line-height: 1.6;
 12    background-color: #f4f4f4;
 13    color: #333;
 14    padding: 20px;
 15}
 16
 17/* Header styles */
 18header {
 19    text-align: center;
 20    padding: 20px;
 21    background-color: #333;
 22    color: white;
 23    margin-bottom: 20px;
 24}
 25
 26header h1 {
 27    font-size: 2.5rem;
 28}
 29
 30header p {
 31    font-size: 1.2rem;
 32    font-style: italic;
 33}
 34
 35/* Navigation menu */
 36nav {
 37    background-color: #555;
 38    padding: 10px;
 39}
 40
 41nav ul {
 42    list-style: none;
 43    text-align: center;
 44}
 45
 46nav ul li {
 47    display: inline-block;
 48    margin-right: 15px;
 49}
 50
 51nav ul li a {
 52    color: white;
 53    text-decoration: none;
 54    font-weight: bold;
 55}
 56
 57nav ul li a:hover {
 58    color: #f4f4f4;
 59    text-decoration: underline;
 60}
 61
 62/* Main content styles */
 63main {
 64    display: flex;
 65    flex-wrap: wrap;
 66    justify-content: space-between;
 67    align-items: flex-start;
 68}
 69
 70article {
 71    flex: 3;
 72    background-color: white;
 73    padding: 20px;
 74    border-radius: 5px;
 75    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
 76    margin-bottom: 20px;
 77}
 78
 79/* Article header */
 80article header h2 {
 81    font-size: 2rem;
 82    margin-bottom: 10px;
 83}
 84
 85article header p {
 86    font-size: 0.9rem;
 87    color: #666;
 88}
 89
 90article section h3 {
 91    font-size: 1.5rem;
 92    margin-top: 20px;
 93}
 94
 95article section p {
 96    margin: 10px 0;
 97}
 98
 99/* Article footer */
100article footer {
101    margin-top: 20px;
102    font-size: 0.9rem;
103}
104
105article footer p a {
106    color: #3498db;
107    text-decoration: none;
108}
109
110article footer p a:hover {
111    text-decoration: underline;
112}
113
114/* Sidebar styles */
115aside {
116    flex: 1;
117    background-color: #fff;
118    padding: 20px;
119    margin-left: 20px;
120    border-radius: 5px;
121    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
122}
123
124aside h3 {
125    font-size: 1.5rem;
126    margin-bottom: 10px;
127}
128
129aside ul {
130    list-style: none;
131    padding-left: 0;
132}
133
134aside ul li {
135    margin-bottom: 10px;
136}
137
138aside ul li a {
139    color: #3498db;
140    text-decoration: none;
141}
142
143aside ul li a:hover {
144    text-decoration: underline;
145}
146
147/* Footer styles */
148footer {
149    text-align: center;
150    padding: 20px;
151    background-color: #333;
152    color: white;
153    margin-top: 20px;
154}
155
156footer p {
157    margin: 5px 0;
158}
159
160footer a {
161    color: #3498db;
162    text-decoration: none;
163}
164
165footer a:hover {
166    text-decoration: underline;
167}
168
169/* Responsive design */
170@media (max-width: 768px) {
171    main {
172        flex-direction: column;
173    }
174
175    aside {
176        margin-left: 0;
177    }
178}

You can follow along with the above article using Visual Studio Code on our YouTube channel. Please also check out the YouTube channel.

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