What is a Domain Name?
A name that identifies one or more IP addresses. For example, the domain name microsoft.com represents about a dozen IP addresses. Domain names are used in URLs to identify particular Web pages. For example, in the URL http://valuedkeywords.com/index.php, the domain name is valuedkeywords.com. 

Applying the Keyword “Domain Name” to a Web Site.
 There are a couple different types of web sites you can produce using the term “Domain Name”, here are a few examples…
You could Review and Compare Domain Name Registrars. I Domain Name Registrar is a Company that distribute Domain Names, for a price of course. For Example, I bought my Domain Name from the Registrar, GoDaddy.
You could create a Domain Name Seller site. This is where you Buy Valuable Domain Names, and then sell them (a Domain Brokerage) for a higher price, however, this could be risky buisiness.