February 2001 || Volume 01, Issue 07

Understanding Top Level Domains

I thought I'd take some time out from the technical details of HTML, and talk about the technical details of serving the web. What prompted this is the recent news about new TLDs. You're all excited about that aren't you? No?

TLDs - or Top Level Domains - are the end parts of all of our domain names. You know, the address you type in to go to a web site. For example, in the address...

http://www.macosjournal.com

...the first part - http - is the protocol. It tells the server we're looking for a HyperText Transfer Protocol document; in short, a web page. Then there's a little punctuation the server needs, then the www part. That of course stands for World Wide Web. It's not a necessary part. You'll occasionally see addresses like http://support.apple.com for example.

The whole thing after the // and up to the first / is the host name. That's the name of the server that is hosting the resource you're looking for. Host names consist of a Top Level Domain, like com, and a second level domain or domain name, like macosjournal. Together they form the domain name macosjournal.com.

The New TLDs

Existing TLDs -- such as com, org, edu -- have been getting used up at a rapid rate. So several years ago the folks that manage these things determined that it would be a good idea to create a few more TLDs, to allow more room for growth and to make more obvious the kind of site to which the address refers. They asked for proposals, judged them over the last year, and on November 16, 2000 approved some new ones. These, along with their intended purposes, are listed below:

• .aero for the air-transport industry
• .biz for businesses
• .coop for non-profit cooperatives
• .info for unrestricted use
• .museum for museums
• .name for individuals
• .pro for accountants, lawyers, and physicians

It's hoped that the biz TLD will take some of the load off the ubiquitous com, but that remains to be seen. After all, if I have a domain like thistledance.com (which I do) and I want to avoid confusion in the marketplace in the future, it's likely I'll also register thistledance.biz. So it's not clear yet that there will be much relief in the crowded com TLD.

The others are quite interesting, and may after all relieve the pressure on com. For example, if you are in the airline industry, you now have aero to play with, and you may well drop your com domain -- after a suitably long changeover period of course. Similarly, if you used com because nothing else fit, but you're not really a provider of goods or services for money -- say for example you're funky-newsletter.com -- then you might consider moving your domain to funky-newsletter.info instead. (Incidentally, it took me a while to find a domain I could safely use in that example.)

The name TLD is for personal use, so your personal home page can now be MarthaWashington.name or whatever. Similarly, if you offer professional medical services you might want to use stitches-r-us.pro or something like that.

Certain financial services will likely use coop, but that makes me wonder why there's no bank TLD. Maybe later. The process is ongoing, and the group that is managing TLDs -- ICANN -- is considering a lot more possibilities.

There should be swift movement within the archive and museum world to lay claim to suitable museum TLDs. I imagine it will be only a short time before we see smithsonian.museum and louvre.museum on the web. If I had an address like http://parkscanada.pch.gc.ca/parks/nova_scotia/alex_g_bell/alex_g_bell_e.htm, I know I'd move pretty fast to change it to www.alex_g_bell.museum!

One of the things that will improve because of this, I believe, is that search engines will begin to allow you to restrict your search to one or more specific TLDs. For example, if you want to find out about Alexander Graham Bell, the inventor, you may be able to search within only the museum TLD and thereby retrieve records that directly reflect your interest without getting all sorts of extraneous hits. Similarly you could search the name TLD and find only people sites rather than a few thousand other sites that may have names on their pages but are really about particle physics or other such minor things. In short, the web is getting a little more complex as it grows up.

Tune in next month when I get back to the nuts and bolts of web pagery.

Rob Stevenson - rstevenson@macosjournal.com
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