Ah.. they are talking about a DNS zone file.
Here's one for example..... But they don't need it.. So not sure why they are asking.
It just contains mappings etc.
$TTL    86400 ; 24 hours could have been written as 24h or 1d
; $TTL used for all RRs without explicit TTL value
$ORIGIN example.com.
@  1D  IN  
SOA ns1.example.com. hostmaster.example.com. (
                  2002022401 ; serial
                  3H ; refresh
                  15 ; retry
                  1w ; expire
                  3h ; nxdomain ttl
                 )
       IN  
NS     ns1.example.com. ; in the domain
       IN  NS     ns2.smokeyjoe.com. ; external to domain
       IN  
MX  10 mail.another.com. ; external mail provider
; server host definitions
ns1    IN  
A      192.168.0.1  ;name server definition    
www    IN  A      192.168.0.2  ;web server definition
ftp    IN  
CNAME  www.example.com.  ;ftp server definition
; non server domain hosts
bill   IN  A      192.168.0.3
fred   IN  A      192.168.0.4