The server to query. If no server is supplied, dig will check the nameservers listed in /etc/resolv.conf. The address may be an IPv4 dotted address or an IPv6 colon-delimited address. It may also be a hostname, which dig will resolve (through the nameservers in /etc/resolv.conf).
The domain name to look up.
The type of query to perform, such as A, ANY, MX, SIG, and so forth. The default is A, but you may use any valid BIND9 query type