DNS

• DNS translates a domain name into an IP Address 
  
• Essentially it is used for convenience; It is hard to remember the IP addresses compared to the name
  
• For example :
• When you type www.google.com in a browser, the DNS protocol translates to its IP address; For example

                               www.google.com -------> 74.125.28.106

• DNS primarily uses User Datagram Protocol (UDP) on port number 53 to serve the IP translation requests.
  
• DNS queries consist of a single UDP request from the client followed by a single UDP reply from the DNS server. Look in the diagram for the detail.
  
• Because domain names are alphabetic, they are easier to remember. The Internet however, is really based on IP addresses. Every time you use a domain name, therefore, a DNS service must translate the name into the corresponding IP address. 

DNS is organized in a following tree structure: