A website or URL such as ccm.net is usually identified by the ccm.net which actually depicts the server of the organization. WWW is onl a convention that are used to distinguish a company web server from It's server. But however it has no importance of having www as a prefix.
Many websites use www2, www3 as names for additional web servers handling taffic for the same website but however its up to the website creator to decide for it is unsignificant.
We can conclude that after the protocol http://, all the domain name is actually up to the host organization. One of the main reasons why host organization choose to set up a new web servers is due to traffic and load balancing.