How Search Works - The Story – Inside Search – Google

HOW SEARCH WORKS

From algorithms to answers.

PART 1 OF 3

CRAWLING AND INDEXING

SEARCH STARTS WITH THE WEB. IT'S MADE UP OF OVER30  TRILLIONINDIVIDUAL PAGESAND IT'S CONSTANTLY GROWING.

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Google navigates the web by CRAWLING.

That means we follow links from page to page.

Site owners choose whether their sites are crawled.

We sort the pages
by their content
and other factors.

The index includes text from millions of books from several libraries and other partners.

"The perfect search engine would understand exactly what you mean and give you back exactly what
you want."Larry Page
Co-founder & CEO

Prefer to watch a video about search? Here you go!

Thanks to Street View, we can also include information from the physical world.

The Knowledge Graph provides better answers by organizing information about real world people, places and things.

It's over 100
million gigabytes.

And we keep track of it all inTHE INDEX.

PART 2 OF 3

ALGORITHMS

WE WRITEPROGRAMS  & FORMULASTO DELIVER THE BEST RESULTS POSSIBLE.

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As you search

string theorystring theory

ALGORITHMSget to work looking for clues
to better understand what
you mean.

Based on these clues, we pull relevant documents fromTHE INDEX.

We thenRANKthe results

We don't accept payment to increase a site's ranking.
The most relevant results appear first.

using over200 FACTORS.

The Search Lab

Our algorithms are constantly changing. These changes begin as ideas in the minds of our engineers. They take these ideas and run experiments, analyze the results, tweak them, and run them again and again.

EXPLORE THESEARCH
LAB

All this happens in
1/8th of a second.

RESULTScan take a variety of forms:

1. 1
   

   Knowledge Graph

   Provides results based on a database of real world people, places, things, and the connections between them.
2. 2
   

   Snippets

   Shows small previews of information, such as a page's title and short descriptive text, for each search result.
3. 3
   

   News

   Includes results from online newspapers and blogs from around the world.

1. 1
   

   Knowledge Graph

   Provides results based on a database of real world people, places, things, and the connections between them.
2. 8
   

   Voice Search

   With the Google Search App, simply say what you want and get answers spoken right back to you.
3. 9
   

   Mobile

   Includes improvements designed specifically for mobile devices, such as tablets and smartphones.

1. 4
   

   Answers

   Displays immediate answers and information for things such as the weather, sports scores and quick facts.
2. 5
   

   Videos

   Shows video-based results with thumbnails so you can quickly decide which video to watch.
3. 6
   

   Images

   Shows you image-based results with thumbnails so you can decide which page to visit from just a glance.
4. 7
   

   Refinements

   Provides features like "Advanced Search," related searches, and other search tools, all of which help you fine-tune your search.

PART 3 OF 3

FIGHTING SPAM

WE FIGHT SPAM 24/7TO KEEP YOUR RESULTS RELEVANT.

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The majority of spam removal isautomatic. We examine other questionable documents by hand. If we find spam, we takemanualACTION.

See what we've removed lately

See action taken over time

See types of spam

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When we take action, we attempt to NOTIFYthe website owners.See the growth in spam notifications

Site owners can FIXtheir sites and let us know.See how often this happens

AND THAT'S HOW SEARCH WORKS.

Behind your simple page of results is a complex system, carefully crafted and
tested, to support more than one-hundred billion searches each month.

Learn something interesting? 

 

By the way, in the 86 seconds you've been on this page, approximately
3,317,880 searches were performed.

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