HTML Introduction

HTML Example

<!DOCTYPE html>
<html>
<body>

<h1>My First Heading</h1>

<p>My first paragraph.</p>

</body>
</html> 
 

Example Explained

  • The DOCTYPE declaration defines the document type
  • The text between <html> and </html> describes the web page
  • The text between <body> and </body> is the visible page content
  • The text between <h1> and </h1> is displayed as a heading
  • The text between <p> and </p> is displayed as a paragraph.

HTML Tags

HTML markup tags are usually called HTML tags
  • HTML tags are keywords (tag names) surrounded by angle brackets like <html>
  • HTML tags normally come in pairs like <b> and </b>
  • The first tag in a pair is the start tag, the second tag is the end tag
  • The end tag is written like the start tag, with a forward slash before the tag name
  • Start and end tags are also called opening tags and closing tags
<tagname>content</tagname>


HTML Elements

"HTML tags" and "HTML elements" are often used to describe the same thing.
But strictly speaking, an HTML element is everything between the start tag and the end tag, including the tags:
HTML Element:
<p>This is a paragraph.</p>


Web Browsers

The purpose of a web browser (such as Google Chrome, Internet Explorer, Firefox, Safari) is to read HTML documents and display them as web pages.
The browser does not display the HTML tags, but uses the tags to determine how the content of the HTML page is to be presented/displayed to the user:
Browser

HTML Page Structure

Below is a visualization of an HTML page structure:
<html>
<body>
<h1>This a heading</h1>
<p>This is a paragraph.</p>
<p>This is another paragraph.</p>
</body>
</html>


HTML Versions

Since the early days of the web, there have been many versions of HTML:
Version Year
HTML 1991
HTML+ 1993
HTML 2.0 1995
HTML 3.2 1997
HTML 4.01 1999
XHTML 1.0 2000
HTML5 2012
XHTML5 2013


The <!DOCTYPE> Declaration

The <!DOCTYPE> declaration helps the browser to display a web page correctly.
There are many different documents on the web, and a browser can only display an HTML page 100% correctly if it knows the HTML type and version used.

Common Declarations

HTML5

<!DOCTYPE html>

HTML 4.01

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">

XHTML 1.0

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">


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