What is the difference between domain names that begin with www and those that do? Not much. Www is technically a subdomain of your main domain, even though it's usually used as the front page. Regardless, you should add a file to your hosting account that redirects people to either the www or non-www version of your page. This will also keep search engines from seeing your site as two duplicates, which can cause you ranking problems.

To do this, you will need to FTP into your root account (where your website files are located) and look for a file called .htaccess (starts with a period). If it's there, you will need to drag it to your desktop and open it with any text editor or word processor.

Add the following anywhere in the file:

RewriteEngine On
RewriteCond %{HTTP_HOST} yourdomainname.com
RewriteRule (.*)$ http://www.yourdomainname.com/$1 [L,R=301]

Save it, and drag it back to your host. It may be wise to rename the original file that is still sitting on your host to something else so you have a backup.

If your host doesn't have that file on it, all you have to do is create one in Notepad or any text editor, drag it to your host, and then rename it to .htaccess (again, starting with a period).

Now if you type your domain name into a browser without the www, it should automatically change to the www version. If you want the opposite effect, simply swap the two domain names in the .htaccess file.