Wednesday, 23 November 2011

Chapter-1 Introduction


History
In 1980, physicist Tim Berners-Lee, who was a contractor at CERN, proposed and prototyped ENQUIRE, a system for CERN researchers to use and share documents. In 1989, Berners-Lee wrote a memo proposing an Internet-based hypertext system. Berners-Lee specified HTML and wrote the browser and server software in the last part of 1990.

What is HTML?
·         HTML is a language for describing web pages.
·         HTML stands for Hyper Text Markup Language
·         HTML is not a programming language, it is a markup language
·         A markup language is a set of markup tags
·         HTML uses markup tags to describe web pages

HTML Tags
·         HTML markup tags are usually called HTML tags
·         HTML tags are keywords 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
·         Start and end tags are also called opening tags and closing tags

·         HTML Documents = Web Pages
·         HTML documents describe web pages
·         HTML documents contain HTML tags and plain text
·         HTML documents are also called web pages
The purpose of a web browser (like Internet Explorer or Firefox) is to read HTML documents and display them as web pages. The browser does not display the HTML tags, but uses the tags to interpret the content of the page:
<html>
<body>
<h1>My First Heading</h1>
<p>My first paragraph.</p>
</body>
</html>

Example Explained
·         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