When you register a domain name, you must provide a name, address, email, etc. as the "registrant" of that domain.  By default, that information is publicly available to anyone who looks up the WHOIS information about a domain.  For an example, go to http://www.dnsstuff.com/tools/whois.ch?ip=pepsi.com and you'll see "who is" the registrant for pepsi.com.

For most businesses, having the registrnt information publicly available is perfectly acceptable, like the pepsi example here... it simply provides corporate contact information.  But for small, one owner businesses, where the business address is also the owner's personal residence, or for personal websites, it may not be wise to allow this information to be publicly available, given the current concerns with identity theft.  Remember that by default, it is publicly available to anyone with access to the Internet.  Remember that all of this DNS stuff came about before less-than-scrupulous folks started using the Internet to retrieve personal information for the purposes of identity theft and fraud. 

Recognizing this as a concern, domain registration companies have started offering an optional service which will protect your private information.  3Essentials in conjunction with our domain registration partner also offer this as an option, which is called "private registration". 

Private registration will list the registrant as "Domains By Proxy", and your personal information will be unavailable publicly.  You will still have full control over the domain registration and it's options.  Private registration is available as an add-on to domain registration, and can be added when you first register a domain, or even after, as noted here:

• You haven't registered your domain name yet?
  • when you register your domain, look for the "add-on" option of "private registration" and add it to each domain you're registering that you want to protect in this manner.
• You have already registered your domain name with 3Essentials
  • Log into our domain registration management interface at http://www.3essentials.com/domain-registration.asp#top
  • click on MANAGE DOMAINS
  • you'll see a list of your domains, click the UPGRADE DOMAIN link to the right.
  • you'll find "private registration" is an available option there.
• You have already registered your domain name with a different registrar
  • check with your current registrar to see if they have something similar to "private registration" available.  If not, you can TRANSFER the domain name to us, and then use our private registration service.