A
CNAME is simply an alias for a host record.
CNAMEs allow you to have more than one DNS name
for a host record. CNAME records point back
to the A record. So if you change your IP address
in your A record, all your CNAME records will
automatically follow the new IP of the A record.
The
alternative solution is to have multiple A records,
but then you would have multiple places to change
the IP address which increases the chances of
error. Using CNAMEs is just more efficient.
The most common CNAMEs are www and ftp.
Domains