20 June 2008

How Web Pages Work

Have you ever wondered how a Web page works? Have you ever wanted to create your own Web page, complete with titles and text and graphic icons? Have you ever heard the word "HTML" and wondered what it means? If so, then read on...

At this moment, it is nearly guaranteed that:

• You are using a computer, personal digital assistant (PDA), or iPhone.
• You are using a Web browser to read this page, and that browser could be Microsoft Internet Explorer, Firefox, Netscape, or Opera.

In order to talk about Web pages and how they work, you will want to understand four simple terms (and if some of this sounds like technical mumbo-jumbo the first time you read it, don't worry):

• HTML stands for Hyper Text Markup Language. A "markup language" is a computer language that describes how a page should be formatted. If all you want to do is display a long string of black and white text with no formatting, then you don't need HTML. But if you want to change fonts, add colours, create headlines, and embed graphics in your page, HTML is the language you use to do it.
• A Web page is a simple text file that contains not only text, but also a set of HTML tags that tell the Web browser how the page should look when it is displayed. The tags tell the browser to do things like change the font size or colour, or arrange things in columns. The Web browser interprets these tags to decide how to format the text onto the screen.
• A Web browser, like Netscape Navigator or Microsoft Internet Explorer, is a computer program (also known as a software application, or simply an application) that does two things:
  • It knows how to go to a Web server on the Internet and request a page, so that the browser can pull the page through the network and into your machine.
  • It knows how to interpret the set of HTML tags within the page in order to display the page on your screen as the page's creator intended it to be viewed.
• A Web server is a piece of computer software that can respond to a browser's request for a page, and deliver the page to the Web browser through the Internet. You can think of a Web server as an apartment complex, with each apartment housing someone's Web page. In order to store your page in the complex, you need to pay rent on the space. Pages that live in this complex can be displayed to and viewed by anyone all over the world. Your landlord is called your host, and your rent is usually called your hosting charge. Every day, there are millions of Web servers delivering pages to the browsers of tens of millions of people through the network we call the Internet. A computer that runs a computer program as described above is also called a Web server.

Let's take a look at the "guts" of a Web page. This is the original text and HTML tags typed by the author and interpreted by the browser to produce the Web page you actually SEE on the Internet. [Note: this only works in a browser and not in your e-mail program. Click here to view this in your browser.] With your mouse, right-click on any blank portion of this page and choose "View Source." A new window will appear, displaying words and characters, some of which may look pretty technical and foreign. These words and characters are, collectively, the HTML. Each element within that code is known as an HTML tag. Don't be intimidated by how complex it looks - you'll be surprised at how easy it really is. When you are finished viewing the page's source code, close the source page to return to this Tutor Tip. You can look "behind the scenes" of almost any page on the Internet this way.