Recently Google announced that they processed 1 trillion (1,000,000,000,000) unique URLs on the web at the same time.
This graph of one trillion URLs is similar to a map made up of one trillion intersections. So multiple times every day, we do the computational equivalent of fully exploring every intersection of every road in the United States. Except it’d be a map about 50,000 times as big as the U.S., with 50,000 times as many roads and intersections.
Also, they estimate the number of individual web pages is growing by several billion pages per day.
Given these mind-boggling numbers it is truly amazing the speed and accuracy of the results of individual Google searches.