There is a large variety of search engines available but only a few that really matter. This article will look at the differences between the current top search engines: Google, Yahoo! and MSNsearch. Search engines today have spiders that crawl the internet to index sites. These no longer require human editors, so sites do not have to be submitted to the search engine to be included in the index.  The vast majority of sites listed are not manually submitted for inclusion.  

The article on How Search Engines Work will be helpful in giving you a better understanding of search engines. The following lists the main functions of the top three search engines:

How The Top Search Engines Work

Google

• Fully automated. Robots called “spiders” crawl the web on a monthly basis and find sites for inclusion in the Google index.
• Does not involve human editors, it is NOT necessary to submit your site to Google in order to be included in their index. In fact, the vast majority of sites listed are not manually submitted for inclusion.
• Does not accept payment for inclusion (known as "paid inclusion") of sites in their index, nor for improving the rank of sites in their results.
• Offers advertising opportunities adjacent to their search results which are always clearly labeled "Sponsored Links."
• Ranks based on popularity (number of pages linked from).
• Source: How Google indexes a site

Yahoo

• Index is more than 99% populated through the free crawl process.
• Offers several ways for content providers to submit web pages and content directly to the Yahoo! Search index and the Yahoo! Directory:
• Yahoo!  Search Submission

Submit Your Site for Free
Site Match™ and Site Match Xchange
Pay-For-Performance™

• Yahoo! Directory Submission
  Yahoo! Express
  Yahoo! Standard

• Ranks based on relevancy (keyword density).
• Source: How Yahoo! Works
• Additional Information: Yahoo! Services Explained

MSNsearch

• There is a webcrawler, the MSNBot, which indexes sites.
• An index generator stores the information.
• A query server acts as the matchmaker between your search terms and the site index.
• Source: How MSN Search Works

Applying Search Engine Knowledge

A good understanding of how the search engines index sites should help to optimize intelligently. The following resources will add to a general understanding of how search engines function and the search needs that they meet:

You may find that you have specific search needs. Check out this chart to see your options:

• Choosing the best engine for your needs 

The following charts detail what features various search engines accommodate:

• Search Engine Features Chart
• Best Search Tools Chart

Back to Search Engine Optimization Checklist

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