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How to use HTML 3.2

Chapter 1 -- Understanding the World Wide Web

Chapter 1

Understanding the World Wide Web


CONTENTS



One of the best things about the World Wide Web is that it's just as easy to create Web pages as it is to browse them. The key to publishing on the Web is having a firm understanding of Hypertext Markup Language (HTML). Despite the intimidating name, HTML is extremely simple to learn and use. By the time you finish this book, you'll be well on your way to becoming an HTML wizard.

Before diving head-first into the language of HTML itself, it will help you to understand a little bit about how the World Wide Web works. After all, HTML is designed to guide users through the vast and tangled resources of the Web. As an HTML author, you will need to understand some of the basics behind the architecture of the World Wide Web. Knowing how the Web works, as well as when it doesn't and why, can help you make important decisions about how to construct your own Web pages.

It would be impossible to describe in detail the inner workings of the Web in a single chapter. With that in mind, this chapter provides you with a "refresher course" on the basics. Armed with this basic knowledge, you'll be able to move on to writing your own Web pages in a very short time.

How the World Wide Web Works

The World Wide Web is a vast collection of information that is spread across hundreds of thousands of computers around the world. When you access a document on the Web, there's a lot going on behind the scenes. Here's a very simple and brief description.

Tip Sheet



  1. The World Wide Web is a network of thousands of computers, all of which fall neatly into two categories: clients and servers. Through the use of special software, they form a kind of network called, not surprisingly, a client-server network.
  2. Servers store information and process requests from clients. Then they send the requested information to the clients. This information includes all kinds of data, including images, sounds, and text. Servers also send instructions to the client on how to display all this information. These instructions are sent in the form of Hypertext Markup Language (HTML).
  3. Clients make requests for information and then handle the chore of displaying that information to the end user. When you are using a Web browser to navigate the Web, your browsing software is acting as a client.
  4. The World Wide Web is a distributed network. That means there is no central computer for the World Wide Web. Any server on the Web can be accessed directly by any client. If a server on the World Wide Web malfunctions, it doesn't affect the performance of other servers.
  5. Users navigate the World Wide Web through the use of hypertext links. When you select or click on a hypertext link, you go to another area on the Internet. Almost all of the documents on the Web are interconnected through the use of hypertext links.
  6. Most of the documents on the World Wide Web are written in Hypertext Markup Language (HTML). HTML provides instructions for the client software on how the document should be displayed. HTML also contains information about how to link up to other documents on the Web.

How Do URLs Work?

Almost every item of information on the World Wide Web can be accessed directly. That's because every document, file, and image has a specific address. These addresses are called Uniform Resource Locators (URLs). URLs are used by Web browsing software to locate and access information on the World Wide Web. Think of URLs as postal addresses for the Internet.

Tip Sheet

  1. The first part of the URL is known as the protocol. This is almost always http://, which is short for Hypertext Transfer Protocol. Some URLs start with a different protocol, such as ftp:// or news://. If you're accessing a document on your local machine instead of on the Web, the URL will begin with file://.

    Figure 1.2 :

  2. The second part of the URL is known as the domain name. If you've used e-mail on the Internet, you're probably already familiar with domains. The domain represents the name of the server that you're connecting to.

    Figure 1.3 :

  3. The third part of the URL is called the directory path. This is the specific area on the server where the item resides. Directory paths on Web servers work a lot like they do on your desktop computer. To locate a particular file on a server, you need to indicate its directory path first.

    Figure 1.4 :

  4. The fourth part of the URL is called the document file name. This indicates the specific file being accessed. This is usually an HTML file, but it can also be an image, sound, or another file.

    Figure 1.5 :

  5. Sometimes the URL contains a fifth part, known as the anchor name. This is a pointer to a specific part of an HTML document. It's always preceded by the pound sign (#). Anchors are especially useful for large documents.

How to Use a Web Browser

Your Web browser is your gateway to the World Wide Web. A browser is the client software that allows you to access and view any document on the Web. There are a number of Web browsers that you can use to access the Web, and the number of choices available grows every month.

Even if you're an accomplished Web surfer, it's a good idea to keep up to date on the most popular browsers. Different Web browsers have different features, and they all display Web pages with slight variations. Older Web browsers, which are still in widespread use, often have trouble displaying some of the newer HTML 3.2 features. If you're planning to create Web pages with HTML, you'll want to test them with a number of different Web browsers.

In this section, we'll take a look at Netscape, which is the most popular browser available today.

Tip Sheet

  1. To navigate to a Web page, you can type in the URL for the page here.
  2. Use these directional buttons to navigate backward and forward through the list of documents you have recently accessed.
  3. The button with the house on it always takes you back to your home page, no matter where you are. By default, most browsers set this button to display their home page, but you can specify the URL for your home page in the Options menu.
  4. Text that is highlighted in a different color usually indicates that it is hypertext. When you click on this hypertext, your Web browser follows the link to a another place on the Web. This is the basic form of navigation on the World Wide Web.
  5. The status bar keeps you informed about the progress of a page as your Web browser loads it. Some Web browsers will use the status bar to let you know the URL of the page you're currently on, or the URL of the page that a hypertext link points to.
  6. Experiment with your Web browser to get an understanding of how navigation works on the World Wide Web. It's a good idea to use a few different browsers and note the differences. Knowing how users browse the Web is an important part of understanding how you should construct your own HTML pages.

How to Use a Hypertext Link

Using a hypertext link to move from one place to another is one of the most common activities on the World Wide Web. In fact, hypertext links are the very essence of the Web. This lesson explains how to use a link and describes a little of what happens behind the scenes.

Tip Sheet

  1. To find a link on the page, look for text that's displayed in a different color. By default, hypertext links you haven't used are blue. Links you've already visited are purple. These colors can be changed, however.

    Figure 1.8 :

  2. Using your mouse, place the pointer over the hypertext link and click. There will be a brief delay after you press on the hypertext link.
  3. During this delay, your browser client is contacting the Web server referenced in the hypertext link's URL. It is attempting to retrieve the referenced document.

    Figure 1.9 :

  4. Once the contact has been established, your browser begins displaying the new document.
  5. Not all links appear as text. Many links appear in images, such as buttons or icons. Sometimes a colored border will appear around the image, or it will be designed to look like a button. In many browsers, the cursor will change to a hand when it passes over a hypertext link. These visual clues help the reader understand that it is a link. However, sometimes there are no visual clues. Understanding the need to provide visual clues is an important part of being an HTML author.