A rectangular text box lies near to the middle of your web browser and there is a search button to it's right. A user enters a query into the text box, hits the search button and... voila! The search returns various results scattered across the page. Wait, is that all? If you take a closer look, you can see that the search results are not limited on a single page, but across numerous pages with more than a million results. Ever wondered how do you get all this information right infront of your eyes?

This is what search engines do. If search engines didn't exist, it would have been nearly impossible to find and locate various content of your choice across the web just by typing url's, because there are nearly or more than a billion of url's and many more webpages. A search engine is a software that is designed to search information across the web.

Here's a simple idea of how a search engine works. There are 3 pieces of software that a search engine uses:-

• Spider software: This is a software robot that searches various internet pages, scans it's content and adds it to the search engine indices. This process is called Web crawling. To build it's list of words, the spider starts out scanning the most popular webpages and heavily used servers, indexing various words within the page (especially the title, subheadings, meta tags and other words of relative importance), and also other links within the page. It then searches the pages within these links and so on.
• Index software: The information gathered by the spider software from the webpages is sent to the index software to be analyzed and stored. Therefore the software makes sense of the text, url's and other information gathered, then it stores the information in a useful way by assigning weight to each entry through various algorithms according to relevance (title, subtitles, links, meta tags etc.), encodes this information to save space, and finally records all this information to make it available to found as quickly as possible by building hash tables.
• Query software: This is actually the front-end of the search engine. When you type various keywords into the search engine (query) and click search, the search engine tries to match these words with relevant webpages. Actually the query software hashes the keyword into the table created by the index software, finds out the best matching words in these tables and thus the corresponding links to webpages are listed in the Search Engine Results Page [SERP]. More complex queries makes use of Boolean operators (AND, OR etc.) to extend and refine the terms of the search.

Different results for various search engines?

Since different search engine employs different algorithms and formulas for assigning weights to the words listed in it's index, and also different crawling habits for their spiders, a query for the same word on different search engines will produce different results across various pages. This is the reason why you don't get the same list of results and page order for Google, DuckDuckGo, Bing etc for the same search.

• Google's priority ranking system is based on the number of backlinks to judge how important a webpage is. Hence topic specific searches may not give you the best results on Google, and is dependent on the popularity of a website.
• Google is unreliable for searching for deep web, referred content and searches are mainly limited to surface, visible web.
• Also the number of results for a specific query returned by Google is too many, most of which may not even match what we intended to get. Hence the quality of the search degrades.
• Google search lists all kinds of results whether they are credible or not and hence you get a mixture of trustworthy and non trusthworthy results.
• The search engine has sparked privacy concerns all over the web by tracking your search habits and also displays 3rd party advertisements based on your behaviour. Google also saves your search and clicks history.
• Here are the other criticisms of Google Search at Wikipedia

Here we discuss about various excellent alternatvies for Google search engine, each having their own specific goals and how they could be more useful to you in different ways.

Note: This article is a stub only. I'll review all the search engines and update the article soon.

To be Reviewed: -

• Ask
• Bing
• Blekko
• Dogpile
• DuckDuckGo
• Mahalo
• Ixquick
• Yahoo
• Yippy!

You might want to check these categories too:-

• Best Free Web Browser
• Best Free Internet Safety Check
• Best Free Website Link Checker
• Best Free Desktop Search Utility

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• A great new intelligent Search Engine