[LordBane999]

first www stands for world wide web, and it's just a naming thing is all, the fact is it isn't really as the important parts of an address is the middle (msn, google, megaupload, etc.) and the end (.com, .net, .edu, etc.), all it is just fancy naming convention (a prefix), now while it's not needed you may come across other sites that may use or need other prefixes (like www2. for example)