Overview of HTML

Some important terms and their meaning:

• Web server: a system on the internet containg one or more web site
• Web site: A collection of one or more web pages
• Web pages: Single disk file with a single file name
• Home pages: First page in website

• WWW: World Wide Web
• W3C: World Wide Web Consortium
• HTML: Hypertext Markup Language
• URL: Uniform Resource Locator

 World Wide Web (WWW):

• The World Wide Web (WWW) is most often called the Web
• The Web is a network of computers all over the world
• All the computers in the Web can communicate with each other.
• All the computers use a communication standard called HTTP (Hypertext Transfer Protocol)

How does the WWW work?

• Web information is stored in documents called Web pages
• Web pages are text files stored on computers called Web servers
• Computers reading the Web pages are called Web clients
• Web clients view the pages with a program called a Web browser
• Popular browsers are: Internet Explorer, Netscape Navigator/Communicator, Safari, Mozilla, Konqueror, and Opera
• Other browsers are: Omniweb, iCab, etc.

How does the browser fetch pages?

• A browser fetches a Web page from a server by sending a request
• A request is a standard HTTP request containing a page address
• A page address looks like this: http://www.someone.com/page.html
• A page address is a kind of URL (Uniform Resource Locator)

How does the browser display pages?

• All Web pages are ordinary text files
• All Web pages contain display instructions
• The browser displays the page by reading these instructions.
• The most common display instructions are called HTML tags
• HTML tags look like this:
• <p>This is a Paragraph</p>

What is an HTML File?

• HTML stands for Hypertext Markup Language
• An HTML file is a text file containing small markup tags
• The markup tags tell the Web browser how to display the page
• An HTML file must have an htm or html file extension
• .html is preferred
• .htm extensions are used by servers on very old operating systems that can only handle “8+3” names (eight characters, dot, three characters)
• An HTML file can be created using a simple text editor
• Formatted text, such as Microsoft Word’s .doc files, cannot be used in HTML files

HTML Tags

• HTML tags are used to mark up HTML elements
• HTML tags are surrounded by angle brackets, < and >
• Most HTML tags come in pairs, like <b> and </b>
• The tags in a pair are the start tag and the end tag
• The text between the start and end tags is the element content
• The tags act as containers (they contain the element content), and should be properly nested
• HTML tags are not case sensitive; <b> means the same as <B>
• XHTML tags are case sensitive and must be lower case
• To ease the conversion from HTML to XHTML, it is better to use lowercase tags