How Search Engines works?

 Most of the search engines, including Google work on web crawling, indexing algorithm and page rank. The search engine crawls hundreds and thousands of WebPages and maintain an Index which they use to search based on the search keywords. Better the indexing algorithm, better is the search performance of the search engine. The search indexing algorithm is a confidential property of the search engine and is not shared by the search engine company. The search engine companies regularly updates the algorithm to optimize the performance of the search engine.

Googlebot is Google’s web crawler which crawls across the web finding and retrieves pages.  Googlebot finds pages based on:

1. The webmaster can submit a URL to Googlebot at: www.google.com/addurl.html
2. Googlebot finds the web page by crawling the web

Googlebot submits the full text of the page to Google Indexer which creates a database where indexes are sorted alphabetically based on search terms. Each index stores a list of documents where these terms appear.

Google maintains two separate index:

1. Main Index  - Where google query executes
2. Supplementary Index – This is a compressed summary index

Google query processor includes the page rank algorithm which ranks every page based on the relevance of the page to the query. A webpage with higher page rank is shown above the webpage with a lower page rank in the google search result.

You can check your website’s page rank at: http://www.prchecker.info/check_page_rank.php