How to make Google,Yahoo,Bing Search Engine works?

Well,everybody is so curious that how search engine actually works.To understand clearly,it is classified into four steps.

Part=1:Search

The search engine uses algorithms (mathematical formulas) to determine exactly what you're looking for,adding in synonyms("tastiest treats"),anticipating your terms before you have even finished typing,and offering corrections in case you've made a mistake(did you mean"best deserts" instead of "best desserts"?).

Part-2:Search 

Your request is sent to the search engine's servers.Here,the company that owns the search engine maintains a massive index of all the words,photos,videos,songs,and other data strewn across the World Wide Web.This information-enough to fill hundreds of millions of gigabytes-is continuously collected and updated by programs called "spiders" that crawl across the Web and sift through it's information.

Part=3:Collect

From it's index,the search engine gathers every Webpage with content that matches your search term.Results are filtered based on hundreds of factors, including the pages'age,the number of people who have visited the pages,their estimated reliability,and more.

part4:Voila!

The results are ranked as links in your Web browser,with the most relevant Web pages at the top of the list.