DNS, Domain Name System, computers and other networking devices understand digital data in the form of 1s and 0s, (binary), these can make up an IP address, allowing a computer to access remote sources, such as web addresses. 

The function of DNS is to resolve these IP addresses to domain names for the users and back again for computers to understand.  For example, www.internet-central.net has no meaning to a computer, it must be resolved using DNS to discover the source IP address of 212.57.232.65.  The computer can then go through the process of communicating with network devices to display the web page.