Domain name server(DNS) is the system that is used to translate human-memorable domain names like listedhosting.com and hostnames like my.listedhosting.com into the corresponding numeric Internet Protocol (IP) addresses as well as to identify and locate computer systems and resources on the Internet.

When you use an alphanumeric address like "listedhosting.com" your computer needs to understand what numerical IP address it should contact to show up the content. Domain name server is a server responsible for keeping the file that contains information about the domain name(s) and corresponding IP addresses (zone file) as well as for providing the above-mentioned information during DNS queries.