You use www for the same reason that the ftp server is ftp.X and the mail server is mail.X. This allows organisations to have logical service locations separate from their current configured location.
So, www is your web service.
If you'd like a proposal, add a new type of DNS record, like the MX record, specifically for HTTP.
So, www is your web service.
If you'd like a proposal, add a new type of DNS record, like the MX record, specifically for HTTP.