How Google Works – A Very Cursory Explanation
As we all know, Google is the #1 search engine in the world. Millions of people use it every day, with the company generating billions of dollars each year through its ads. But how does Google work? Here we provide a very basic overview of how the search engine functions and comes up with its organic search results (we won’t discuss Google ads or pay-per-click advertising).
Like most search engines, Google uses web crawlers to find content. These automated programs retrieve the text on each web page, give it to Google’s indexer, then uses the links on the web page to crawl off and find new content. The more links there are to your site, the more quickly Google’s web crawlers will find it.
The Google indexer takes the content it receives from the web crawlers and stores it in a reverse index. The index is sorted alphabetically by search term, with each search term linked to a list of web pages and documents where it can be found. Stop words like “the,” “or,” “of,” etc. are ignored in order to improve search performance.
Once indexing is completed, Google uses a super-secret algorithm to calculate the PageRank, which is a relevancy score assigned to each web page. Google considers over 100 factors when determining PageRank; however, three of the most important factors are
- the frequency and location of search terms within the web page
- how old the web page is
- how many incoming links the web page has
Many SEO experts believe that the third factor – the number of inbound links – is the most important factor in determining PageRank.
When a user types a search term into Google, it uses the reverse index to create an initial set of results. The results are sorted by PageRank, various filters are applied, and the final organic search results are displayed, with local websites promoted towards the top of the results. It takes less than a second for the results to appear once the user enters a search term.
There are plenty of details we didn’t cover, but this should give you a general idea of how Google works. Thanks to this popular search engine, searching for information on the Internet is as easy as typing a phrase and clicking a button.