For this purpose we have the Domain Name System, DNS for short. The most important task of the DNS is to map domain names to IP addresses. E.g. if a user types ftp cc1.kuleuven.ac.be, this must be mapped to ftp 134.58.8.32. Using tables the DNS will map cc1.kuleuven.ac.be to 134.58.8.32, and the ftp application will then use the IP address.
Name servers are special servers who can solve DNS requests.
If the name server does not know the answer itself, it will either contact other name servers to answer the question, or it will point the requestor to another name server. It is important that each Internet host is configured with the IP addresses of more than one name server, because a single name server can be down or unreachable. Mapping names to addresses is called resolving in DNS terminology. A name server can be responsible for a part of the name space, which means that the tables for that part of the name space are managed on that server. Other systems do it in reverse order.