Some people don’t care what you call them as long as you call them. Some Web site owners feel the same. Yet a Web site’s “domain name” can be a powerful way to get people through your virtual door.

A domain name, as it’s most commonly understood, is a Web site’s address expressed in an individual and memorable way, such as “yourname.com.” Anyone can obtain a domain name, from multinational companies to grade school children.

If you have a Web site or work with one, you may know what the domain registration process is. You first find out if the name you want is already taken by going to a whois server such as InterNIC’s Whois Search (http://www.internic.com/whois.html) or Whois.com (http://www.whois.com).

Think carefully about the name and how it might look. Mistakes have been made, sometimes humorously. Experts Exchange, a site for computer programmers, initially could be found at expertsexchange.com. Pen Island, a custom-made pen vendor, chose the domain name penisland.net.

One easy solution is to use a hyphen. Experts Exchange changed its domain name to experts-exchange.com. Pen Island has kept its domain name as is. Based on the layout of its Web site, it apparently regards its customer base as primarily male.

During the years after the World Wide Web went public in 1991, you had to type “http://” and “www.” before the domain name to get to the site. The letters HTTP stand for hypertext transfer protocol (i.e., the way Web pages are transmitted over the Internet), and WWW is short for World Wide Web, the Web’s full name. Today, in most cases, all you have to type is the domain name, and sometimes you can even leave out the .com. Domain names are case-insensitive, so there’s no need to capitalize.

The part at the end of a domain name, such as .com, is called the top-level domain. Other examples include .biz, .edu, .gov, .info, .int, .mil, .name, .net, and .org, though the most popular remains .com. Many countries also have their own top-level domain, from .af for Afghanistan to .zw for Zimbabwe.

After you’ve chosen a domain name and found it isn’t already used, it’s best to act quickly. Hackers have been known to intercept whois queries and register the domain name, offering it to you at a significantly higher price than if you had registered it yourself.

Today you can register a domain name with any of the 500-plus domain name registrars. Before 1999, the only domain name registrar was Network Solutions (http://www.networksolutions.com), which had been granted an exclusive contract by the National Science Foundation. Network Solutions, which manages more than 7 million domain names, is still the registrar for well-known domain names such as nytimes.com, ebay.com, amazon.com, and myspace.com.

But many individuals and businesses have taken advantage of the competitive marketplace for domain names, sometimes after experiencing problems with customer service, registering new domain names, or transferring current domain names to other registrars.

Among the registrars recommended in an online discussion about the subject by those who write about the Internet for a living are GoDaddy (http://www.godaddy.com), Dotster (http://www.dotster.com), DomainDirect (http://www.domaindirect.com), and Sibername (http://www.sibername.com). Prices are generally between $10 and $15 per year, with exotic top-level domains costing more. Bundled or extra services include domain forwarding, e-mail forwarding, and Web space.

Problems can arise when individuals or companies register domain names similar to trademarked business names. This practice, known as “cybersquatting,” is now illegal, as it violates the 1999 Anticybersquatting Consumer Protection Act. One cybersquatting scheme was to try to sell the altered domain name to the trademark owner.

Another scheme that is still active is to create a page full of pay-per-click ads with a domain name that is similar to a trademarked name. People may wind up on these sites by misspelling the names of the sites they want to reach. Microsoft Corp. recently filed suit against three cybersquatters who registered 234 domain names that were similar to Microsoft’s trademarked names.

At other times, trademarked names are used in phishing scams. Criminals use these gambits to try to trick consumers into revealing credit card and other personal information at a site with an official-sounding name.

Some companies have engaged in “reverse cybersquatting”—they register domain names such as xyzcompanysucks.com to prevent critics from using it. Verizon, for instance, registered “Verizonsucks.com.”