A subdomain is a sub-section of your website.  Let me show you what a subdomain is with an example.  Let’s take the domain howguru.com.  A subdomain would be something.howguru.com.  So if you wanted to go to the subdomain “something,” you would type “http://something.howguru.com.” Note that I did not include a “www” before the subdomain “something.”  This is important because sometimes adding a www before a subdomain will get you to the same page and sometimes it will not.  Always default to not using “www” before a subdomain.

Subdomains are often used to organize a site with many different topics or sections.  The subdomains are thought by some to be neater and tidier than making people go to “http://www.howguru.com/something/.” Whether you want to go one route or the other is up to you.  One benefit to subdomains is that you are often able to create email addresses as the various subdomains.  This allows you to create different sections of a site for different people to administer while also giving them all administrative email addresses at their subdomains.