One trillion pages in Google's index

Google announced that its URL index has reached one trillion entries, eight years after passing the one billion mark. Each of the entries represents a unique URL, and there are 150 of those in Google's index for every living person on the planet.

From the official Google blog:
"How do we find all those pages? We start at a set of well-connected initial pages and follow each of their links to new pages. Then we follow the links on those new pages to even more pages and so on, until we have a huge list of links. In fact, we found even more than 1 trillion individual links, but not all of them lead to unique web pages. Many pages have multiple URLs with exactly the same content or URLs that are auto-generated copies of each other. Even after removing those exact duplicates, we saw a trillion unique URLs, and the number of individual web pages out there is growing by several billion pages per day."

The number of web sites on the internet has also been growingly rapidly, and is expected to reach 200 million this year.