Web Address Components
In the illustration above (Web Address Components), the
Protocol "HTTP://" indicates that this address is
for a Web page (HTTPS is for a secure Web page). Some
other common protocols are FTP (file transfer protocol),
which is used to transfer files, but not to display them;
and HTTPS, which encrypts or scrambles the
communication between your browser and the server so
others who may intercept it can't understand it.
Note: Web browsers assume the protocol is HTTP
when it's omitted from the address. So you will often see
an address advertised without the protocol
like www.E-List.Net. No need to precede it with
http://.
The Domain name identifies the host computer or
Web server where the page lives. Domain names have two or
more parts, separated by periods. The two parts that are
always present are the top level domain —that's the
last part, net—and the secondary domain
—just to the left, E-List.
When the Domain Name System was designed, the top level
domain (TLD) was intended to indicate what kind of
organization the domain belonged to. These days anyone can
get one of the four main TLDs, but most organizations
still follow the original guidelines, and so knowing those
guidelines can be useful.
For example, net indicates an organization
involved in the Internet infrastructure, com
indicates a commercial business, org is a
noncommercial organization, edu a college or
university, gov a government office. The top level
domain can also indicate the country in which the domain
is registered. For example, ca is in Canada and
au is in Australia.
The secondary domain is usually some form of the host
organization's name—in this case "e-list" is a form of
E-List. For more information on the Domain Name System,
visit
InterNIC.
The Directory path, the next part of a Web
address, provides directions to where a Web page is stored
on the server. Web servers are on computers with file
systems much like your computer's: files are grouped in
folders or directories, and directories can have
subdirectories. The directory path is an efficient
way of writing the sequence of directories one would have
to open to get to a file.
The Name of the Web page is the last part of a
Web address. The file name will almost always have an
extension—a period and a few letters at the end that
specify the file type. If the address doesn't name a
specific file, most Web servers will automatically give
you a default index page. If there isn't an index page,
your browser will do one of two things: show a list of the
directory contents, or display an error message.
So, to recap, the address in our previous illustration
tells the Web browser to use Hypertext Transfer Protocol
to ask the Web server at www.E-List.Net for the
file named index.html, which is in the directory
named home.
