Domains Must Sell

The level of domains doesn't stop there. Each second level domain can have any name as a third level of domain. WWW is such an example. Every domain (regardless of the level) must be associated with at least one IP address. Therefore "domain. com" and "www. domain. com" are different domains and each has its own IP address which can be the same. We may have various services associated with our domain like FTP or private access area. In such case it makes sense to assign each service to its own third level sub-domain. One of the services could be web pages at www sub-domain. But having the www domain is not mandatory. You could have your main domain pointing to your website. It is the perception of the people that each web address should start with WWW.