Question: When I search a file on my HD in Windows 7 or Windows XP it takes some minutes to finish the process. If I fill in a search term in Google, the answer is on my screen in milliseconds
How is it possible for Google to search the Internet, which is many times larger than my hard drive, faster than my OS can search my computer? Is it only a matter of computing power and the right algorithm?
Answer: Google is not searching the internet: it is searching an index. Google has huge server farms which are constantly scanning and indexing the internet. This process takes a lot of time, just like the search of your unindexed hard drive. In Windows 7, there is an option to index your hard drives. This process takes some time at first but once it is up and running the results of a search will be instantaneous.
If you want to know more about how the Google search works you can read Google’s article “How Search Works” or read the article “How Stuff Works: How Google Works“.