Getting Started with Adobe Dreamweaver CS5 - New Perspectives on Adobe Dreamweaver CS5, Comprehensive - page 6

Common Web Page Elements
Now that you understand what a Web page is and how your computer accesses a Web
page on the Internet, you will examine some elements that are common to all Web
pages: the Web address, hyperlinks, and content.

Web Address
Every Web page that is posted to the Internet has a Web address. Just as your residence
has a unique street address that people use to locate where you live, and as a fi le on
your computer has a unique path used to locate where it is stored, every Web page has
a unique address, called a Uniform Resource Locator ( URL ) that Web browsers use to
locate where that page is stored. A URL includes the information identifi ed in Figure 1-3.

Figure 1-3 Parts of a URL

http://www.nu-design.com/basics/layout.html

protocol domain name filename

machine name folder on Web server file extension

The fi rst portion of the URL indicates the protocol, which is usually HTTP but can
be HTTPS ( Hypertext Transfer Protocol Secure ). HTTPS means that the site is secure
because it encrypts data transferred between a user's browser and the server. Encryption
is the process of encoding and decoding data so that only the sender and/or receiver can
read it, preventing others from being able to understand it. This is important when a user
submits confi dential or credit card information over the Web.
The protocol is immediately followed by “://” which originated from UNIX (a server
operating system) and essentially means “what follows should be interpreted according
to the indicated protocol.” When typing a URL into a browser, if you omit the protocol,
the browser assumes you mean http:// .
The next part of the URL is the machine name , which is a series of characters that the
server administrator assigns to the Web server. Often, the machine name is www, but it
can be any word, phrase, or acronym. It can even be omitted entirely. For example, the
URL store1.adobe.com for the Adobe Store - North America uses store1 as the machine
name, and the URL cnn.com for CNN omits the machine name entirely. Many serv-
ers are confi gured to route the URL with or without a www to the same location. For
example, www.nu-design.com an d nu-design.com both go to the same place.

Because so many sites
use www as the machine
name, include the machine
name if you are unsure of
a site's exact URL.