What does the @8.8.8.8 argument do in dig @8.8.8.8 example.com?
@8.8.8.8
dig @8.8.8.8 example.com
It forces the answer to come from the local hosts file.
It sends the query to the DNS server at 8.8.8.8 instead of the system's default resolver.
8.8.8.8
It asks for the hostname whose address is 8.8.8.8.
It requests a special record type named 8.8.8.8.