Domain Name Server usually abbreviated as DNS is the system used to convert word-based addresses of systems to their corresponding numerical IP address (Internet Protocol). For example http://www.truehost.co.ke to its equivalent IP Address (126.96.36.199).The translation of word based addresses to their corresponding IP addresses is important since that’s what computers use to identify each other on a network such as an internet.
When a website visitor, types the site address in the address bar on his/her browser, they type a human-friendly address (word based address), his or her computer will send the address to a recursive resolver normally operated by the visitor’s Internet service provider which in turn passes the address (word-based address) to DNS Server. The DNS server processes the address passed into its IP address equivalent.
The very first DNS server contacted by the recursive resolver is a Root Server others will refer to it as a Root Name Server. Basically, a Root Server directly answers requests for records by returning a list of authoritative name servers for the appropriate Top Level Domains (TLDs) such as .com. The root name servers are an important part of the Internet setup because they are the first step in converting human readable host names into IP Addresses that are used in communication between Internet hosts (Computer or other network device connected to a computer network).