DNS lookup utility

The -4 option forces dig to only use IPv4 query transport. The -6 option forces dig to only use IPv6
query transport.

server
    is the name or IP address of the name server to query. This can be an IPv4 address in dotted-decimal
    notation or an IPv6 address in colon-delimited notation. When the supplied server argument is a
    hostname, dig resolves that name before querying that name server. If no server argument is provided,
    dig consults /etc/resolv.conf and queries the name servers listed there. The reply from the name
    server that responds is displayed.

name
    is the name of the resource record that is to be looked up.

type
    indicates what type of query is required — ANY, A, MX, SIG, etc.  type can be any valid query type.
    If no type argument is supplied, dig will perform a lookup for an A record.