Name servers play an important part in getting from a web address (or URL) to the actual web page it points to.
When your browser fetches a web page from the server hosting it, it does that using the server IP address. There is a process (domain name resolution) where a domain name (contained in the URL) is ‘translated’ to the appropriate IP address. This process uses the Domain Name System records (DNS records) which are kept by a name server. Each name server can contain these records for several domains (and their sub-domains). Name servers are found by what’s known as a WHOIS lookup.
Here’s an example, lets say you type the following address in your browser’s address bar:
- A WHOIS lookup will be made at the WHOIS authority for
.sedomains to find the name server for
- The name server will be queried on the DNS record for an IP address to
- The browser contacts the IP address the domain resolved to and gets a response that will be sent back to the user
More info on this Wikipedia entry: Domain_Name_System.