HTML Introduction
HTML Example
Code <!DOCTYPE html> <html> <body> <h1>My First Heading</h1> <p>My first paragraph.</p> </body> </html>
Output

My First Heading

My first paragraph.

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
     The <!DOCTYPE html> declaration is the doctype for HTML5.



What is HTML?

HTML is a language for describing web pages.
  • HTML stands for Hyper Text Markup Language
  • HTML is a markup language
  • A markup language is a set of markup tags
  • The tags describe document content
  • HTML documents contain HTML tags and plain text
  • HTML documents are also called web pages



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:




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">
For a complete Learning on "Code Professionally in HTML" visit     Web Technologist- level 1     page.

What is CSS?

  • CSS stands for Cascading Style Sheets
  • Styles define how to display HTML elements
  • Styles were added to HTML 4.0 to solve a problem
  • External Style Sheets can save a lot of work
  • External Style Sheets are stored in CSS files

CSS Demo

An HTML document can be displayed with different styles: See how it works


Styles Solved a Big Problem

HTML was never intended to contain tags for formatting a document.

HTML was intended to define the content of a document, like:

<h1>This is a heading</h1>

<p>This is a paragraph.</p>

When tags like <font>, and color attributes were added to the HTML 3.2 specification, it started a nightmare for web developers.
Development of large web sites, where fonts and color information were added to every single page, became a long and expensive process.

To solve this problem, the World Wide Web Consortium (W3C) created CSS.

In HTML 4.0, all formatting could be removed from the HTML document, and stored in a separate CSS file.

All browsers support CSS today.


CSS Saves a Lot of Work!

CSS defines HOW HTML elements are to be displayed.

Styles are normally saved in external .css files. External style sheets enable you to change the appearance and layout of all the pages in a Web site, just by editing one single file!

For a complete Learning on "Design Good looking Web pages using CSS" visit     Web Technologist- level 1     page.