The HTML <head> Element
The
<head> element is a container for metadata (data
about data) and is placed between the <html> tag and the <body> tag.
HTML metadata is data about the HTML document. Metadata is not displayed.
Metadata typically define the document title, character set, styles, links, scripts, and other meta information.
The following tags describe metadata: <title>, <style>,
<meta>, <link>, <script>, and <base>.
The HTML <title> Element
The
<title> element defines the title of the document,
and is required in all HTML/XHTML documents.
The <title> element:
- defines a title in the browser tab
- provides a title for the page when it is added to favorites
- displays a title for the page in search engine results
A simple HTML document:
Example
<!DOCTYPE html>
<html>
<head>
<title>Page
Title</title>
</head>
<body>
The content of the document......
</body>
</html>
The HTML <style> Element
The
<style> element is used to define style information for a
single HTML page:
Example
<style>
body {background-color: powderblue;}
h1 {color: red;}
p {color: blue;}
</style>
The HTML <link> Element
The
<link> element is used to link to external style sheets:
Example
<link rel="stylesheet" href="mystyle.css">
The HTML <meta> Element
The
<meta> element is used to specify which character set
is used, page description, keywords,
author, and other metadata.
Metadata is used by browsers (how to display content),
by search engines (keywords), and other web services.
Define the character set used:
Define a description of your web page:
<meta name="description" content="Free Web tutorials">
Define keywords for search engines:
<meta name="keywords" content="HTML, CSS, XML, JavaScript">
Define the author of a page:
<meta name="author" content="John Doe">
Refresh document every 30 seconds:
<meta http-equiv="refresh" content="30">
Example of <meta> tags:
Example
<meta charset="UTF-8">
<meta name="description" content="Free Web tutorials">
<meta name="keywords" content="HTML,CSS,XML,JavaScript">
<meta name="author" content="John
Doe">
Setting The Viewport
HTML5 introduced a method to let web designers take control over the viewport, through the
<meta> tag.
The viewport is the user's visible area of a web page. It varies with the thiết bị, and will be smaller on a mobile phone than on a computer screen.
You should include the following <meta> viewport element in all your web pages:viewport
<meta name="viewport" content="width=device-width, initial-scale=1.0">
A <meta> viewport element gives the browser instructions on how
to control the page's dimensions and scaling.
The width=device-width part sets the width of the page to follow the
screen-width of the device (which will vary depending on the device).
The initial-scale=1.0 part sets the initial zoom level when the page is first loaded by the browser.
Here is an example of a web page
without the viewport meta tag, and the same web page
with the viewport meta tag:
Tip: If you are browsing this page with a phone or a tablet, you can click on the two links below to see the difference.
The HTML <script> Element
The <script> element is used to define client-side JavaScripts.
This JavaScript writes "Hello JavaScript!" into an HTML element with id="demo":
Example
<script>
function myFunction {
document.getElementById("demo").innerHTML = "Hello JavaScript!";
}</script>
The HTML <base> Element
The <base> element specifies the base URL and base target for all relative URLs in a page:
Example
<base href="https://www.w3schools.com/images/" target="_blank">
Bỏ qua <html>, <head> and <body>?
According to the HTML5 standard; the <html>, the <body>, and the <head> tag can
be omitted.
The following code will validate as HTML5:
Example
<!DOCTYPE html>
<title>Page Title</title>
<h1>This is a heading</h1>
<p>This is a paragraph.</p>
Note:
W3Schools does not recommend omitting the <html> and <body>
tags. Omitting these tags can crash DOM or XML software and produce errors in older browsers
(IE9).
However, omitting the <head> tag has been a common practice for quite some
time now.
