High Quality Content by WIKIPEDIA articles! Google requires large computational resources in order to provide their service. This article describes the technological infrastructure behind Google's websites, as presented in the company's public announcements.When a client computer attempts to connect to Google, several DNS servers resolve www.google.com into multiple IP addresses via Round Robin policy. Furthermore, this acts as the first level of load balancing and directs the client to different Google clusters. A Google cluster has thousands of servers and once the client has connected to the server additional load balancing is done to send the queries to the least loaded web server. This makes Google one of the largest and most complex content delivery networks.