Domain Name System

• A method that computers use to find the correct IP Address for a given URL, by using a series of servers, that break down the URL, such as the TLD server (Top Level Domain Server).
• Domain Name System (DNS)


  1. URL is sent to the DNS Resolver Server

  2. Resolver checks its cache

  3. If URL isn't there resolver passes it to the TLD (Top Level Domain) Name Sever

  4. TLD Name Server, responds with the address of TLD Server (e.g address of '.com' server)

  5. DNS Resolver Server makes a request to the specified TLD server

  6. TLD server responds with the IP Address of the domain name server ( e.g. 'google.com' IP Address)

  7. DNS Resolver then sends a query to the Authorative Name Server

  8. IP Address is returned to the DNS Resolver from the Authorative Name Server

  9. DNS Resolver responds to the web browser with the IP Address , and the site can be visited
• WWW = World Wide Web - A collection of web pages and other associated files hosted on web servers around the world
• Uniform resource

  locator (URL) The main

  part of a website address
• Once the address has been found , as it has been passed back to each server the address is cached , so it can be found more quickly next time