Zone files

Database file per zone
a sequence of RRs contained in the zone
a standard zone file can also be a part of BIND configuration
Useful Notations
abbreviation of upper domain by 
be careful: prone to errors
    (kame.net. zone file)
    www 3600 IN A 10.0.0.1 ;; for www.kame.net.
    ns  3600 IN NS ns.kogame.org ;; trailing "." is forgotten
"$ORIGIN": the default upper domain
    $ORIGIN kame.net.
    www 3600 IN A 10.0.0.1 ;; for www.kame.net.
@: abbreviation of the zone itself
TTL: time unit can be specified with BIND
e.g.: 1D (1 day), 1H30M (1 hour and 30 minutes)