Your ISP
Router
RouterDNS
DNS
Facebook Server
Router
2. ISP receives the request for Facebook.com.
1. ISP gives your computer an your IP address.
3. DNS translates http://www.facebook.com to 66.220.158.25
4. Router tries to find the quickest way to 66.220.158.25.
7. DNS translates 66.220.158.25 to http://www.facebook.com.
6. Facebook tries to find the quickest way to your IP address.
5. Facebook receives the request for the homepage.
You see the Facebook homepage:
http://www.facebook.com.
You type http://www.facebook.com.
8. Router tries to find the quickest way to your IP address.
9. Your request is returned.