Understanding WWW (Page 1)
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The World Wide Web
How the World Wide Web works
How Do URLs works
How to use a Browser
How to use a Hypertext Link
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.
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.
- Many people consider the World Wide Web and the
Internet to be one and the same. The World Wide Web is only part of the
Internet, but it's growing at a faster rate than any other part.
- You can read about how the Internet works in How to
Use the Internet, Third Edition from Ziff-Davis Press.
- 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.
- 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
- 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
- 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.
- 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.
- 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.
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.
- Be very careful when specifying URLs. The Web is very
unforgiving with URLs, and will only accept exact matches. If you receive a
"document not found" message when trying to access a page on the
Web, make sure the URL is typed in correctly.
- Most browsers allow you to store your favorite URLs as
"bookmarks." Use bookmarks to save yourself the trouble of typing
in the full URL each time.
- 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://.
- 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.
- 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.
- 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
- 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
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
In this section, we'll take a look at Netscape, which is
the most popular browser available today.
- Not all browsers look alike. Read the documentation for
your Web browser for specific details.
- New Web browsers are constantly being released, and
existing ones are updated regularly. Make sure you're using the most recent
version of your Web browser. You can usually find updates on the home page
of your Web browser's publisher.
- To navigate to a Web page, you can type in the URL for
the page here.
- Use these directional buttons to navigate backward and
forward through the list of documents you have recently accessed.
- 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.
- 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.
- 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.
- 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.
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.
- Most Web browsers allow you to change the style and
appearance of hypertext links. Look under the Options menu in your browser.
- You can create a link to any object on the Web. Links
can point directly to images or files as well as to different HTML
- 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
- Using your mouse, place the pointer over the hypertext
link and click. There will be a brief delay after you press on the hypertext
- 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.
- Once the contact has been established, your browser
begins displaying the new document.
- 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.
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