Every time that you request your computer to visit a location on the web, the computer must go through a few key steps to arrive at that address or location. Similar to you looking up the address for a friend in a phone book before heading over to their house. You look through the phone book, using the friends name. You find their location and determine a route to go to their house. For example, you want to visit a site that is http://www.thesite.com. First, the computer looks to the stored DNS cache that might contain information about that site. If the computer does not have that information, it makes a query or contacts your ISP’s DNS or name servers. The information is returned with the IP Address and sends your connection to the right address for http://www.the site.com.
The servers that an individual uses is probably provided by their ISP or their Internet Service Provider. If you use a router, the router is the server for the DNS. In other words your router is the one that is sending the messages directly to your Internet Service Provider and receiving the messages that are transferred to your computer. The computer saves this message in a special cache. Therefore, the next time that your computer sends a request, it is already stored in the computer’s cache. Thus, saving time and connecting the computer faster to the address.