We pick d.root-servers.net, one of the 13 root servers (1), and ask it about arwena.nask.waw.pl and learn that pl is delegated to eight name servers (2), so we ask g-dns.pl where we learn that nask.waw.pl is delegated to four name servers, including bilbo.nask.pl (3), so we ask that one and get the following answer:
The two IP numbers 148.81.254.66 and 193.59.201.28 together
All of the one host names that point to the two IP numbers 148.81.254.66 and 193.59.201.28 together, hereafter referred to as "IP group 1", use the two name servers arwena.nask.waw.pl and vega.pgi.waw.pl together, hereafter referred to as "name server group 2".
The IP number 193.59.201.28
There are two host names that point to the IP number 193.59.201.28.