The document discusses DNS (Domain Name System) servers and how they work. It explains that DNS servers translate human-readable domain names to machine-readable IP addresses in 7 steps: 1) A request is made, 2) recursive DNS servers are queried, 3) root nameservers are queried, 4) TLD nameservers are queried, 5) authoritative nameservers are queried, 6) the IP address record is retrieved, and 7) the answer is received. DNS servers act like a phone book to lookup domain names and allow the internet to function by linking names to IP addresses.