Understanding the domain name
What's with the number then?
What's the URL?
E-mail addresses

Intimidated by those horrific Internet address addresses? Here's a crash course.

Internet addresses like bongo_beans@criminy.com.edu.au look daunting, but they're actually pretty easy to decode if you break them down into bits. Let's start with with the basic building block of Internet addresses -- the domain name.

Understanding the domain name

All Internet sites are, or are part of, a `domain'. The domain name then is where a computer `lives' when it's connected to the Internet.

PC User magazine has a domain name of PCUSER.COM.AU which is easily demystified by reading from right to left:

• The 'AU' in our domain name indicates this is an Australian Internet site. The Net uses standard country codes such as NZ for New Zealand, UK for the United Kingdom, DE for Germany and so on. Domain names in the USA don't have any such code -- when the Internet began as a US military and scientific research project in 1969, no-one ever imagined it would extend beyond American soil to become a global network, let alone the global network that it is today. The letters `US' have since been allocated for Stateside domain names but sightings are rare indeed. You'll even find Australian sites without the `AU' extension -- they're the ones who have registered the name off-shore.
  
• The `COM' part of the address designates PC User as a commercial or business organisation. This is also part of an international standard which includes EDU for educational institutions, GOV for government bodies, MIL for the military defence forces and ORG for non-profit or community groups and others which don't clearly belong in any of the previous categories. The odd one out is NET, which is supposed to be for `networks' but varies from country to country in its useage.
  
• The final component of the address is the name of the organisation, in this case `PCUSER'. Add them all together and you've got pcuser.com.au, and that's where we live online! You may also see an extra name, separated by a dot, in front of the organisation name. This is for those organisations that have more than one entity online.
  

What's with the number then?

Because computers think in numbers not words there's a digital equivalent to the pcuser.com.au address -- it's 203.4.212.41. It's a lot like using a telephone book. When you tell your Web browser to go to our PC User page on the World Wide Web the computer consults an online database, matches the name to the number and away it goes. The browser's status area will actually show the message `Connecting to 203.4.212.41' when it makes contact with our Web page.

What's the URL?

Armed with such an address your computer can navigate its way to almost any place on the Internet, but not being as clever as us humans, it doesn't know what to do when it gets there.

This is how the `Uniform Resource Locator' or `URL' came about. It's a special form of Internet address which builds on the domain name to tell your computer how to handle the data it will be receiving.

Every one of those wonderful places you visit on the World Wide Web has a unique URL which normally begins with http://www -- such as http://www.pcuser.com.au. HTTP stands for `hypertext transfer protocol', the language used by computers to link the Web together and let you jump from one site to another by clicking your mouse. WWW is of course the World Wide Web.

When you type http://www.pcuser.com.au into your Web browser, it knows not only to go to the PC User domain but to display it as a Web page.

The second most common URL is designed to help with transferring files from distant computers onto your own hard drive. This is called `file transfer protocol' or FTP and is written as ftp://ftp.microsoft.com (that URL points to the Microsoft's massive online file library in the USA). There are special programs for FTP operations, although Web browsers also allow you to enter an FTP address and download files.

The first part of the URL -- http or ftp -- is often dropped when referring to the address because Web browsers know to add those codes as soon as they see the www or ftp command immediately preceding the domain name. This shortens the Internet address and makes it easier to remember and print.

Conversely, as soon as you dive into an Internet site, the URL will grow. A Web site with multiple pages will add extra characters after a slash to indicate which page you're looking at.

When you first visit the PC User Web page the URL in your browser's address box is http://www.pcuser.com.au/current.html. Your browser has opened an Internet document named current.html which resides in the root directory of the pcuser.com.au server. Look familiar? It's almost identical to a DOS path such as C:\DOS\README.TXT. In larger sites you'll end up browsing documents nested deep inside sub-directories, some of which will begin with a tilde (~) character because the Net doesn't support spaces in filenames, but every single file on the Internet has its URL.

E-mail addresses

Another way in which the domain name is used is to represent an electronic mail or e-mail address. Their format is username@domainname. The domain name may be your Internet service provider, your employer or the university you attend -- whichever you use to access the Net.

If your Internet service provider is the national OzEmail network and your user name is Matilda your e-mail address would be matilda@ozemail.com.au

Finally, while we don't want to put words into your mouth, how do you pronounce an Internet address? The full stops are read as `dot', so to tell a friend where to find the PC User Web page you'd say, "WWW dot PC User dot com dot ay ewe".

By Rose Vines