GOOGLE.com

Currently the biggest search engine by number of pages indexed in their datacenters and total amount of daily searches.

It is one of the few search engines with the capability of indexing word, pdf and excel spreadsheets. Websites are indexed google own spider called googlebot and can be submitted directly from their submission page or googlebot will find your website through links present in already indexed pages, unless specified in the robots txt file.

Gooogle’s algorithm and search technology are patented and google inc also owns several popular services such as google earth, gmail, adwords and adsense, youtube, books and many others.

There isn’t an exact recipe on how to rank in google search results but usually unique updated content, a good keyword density, a proper on site optimization and most important lots of links coming from relevant sources will do the job.

YAHOO.com

First started as a paid directory (which still exists) until 2004 they created their own search technology after using inktomi and later google search results for some years.

Today yahoo is the second biggest search engine and the most visited web portal online. One of the nicest feature yahoo offers to SEOs is yahoo site explorer which shows the total number of backlinks a website has indexed by yahoo and the total number of pages. In other search engines only a few indexed backlinks are publicly available.

Some popular services provided by yahoo are yahoo mail, answers, messenger and many small business utilities.

Yahoo takes in consideration onsite and offsite optimization equally to rank websites. There is the possibility of suggesting a site directly to yahoo but as google yahoo bot will also index your sited if it finds that websites already in their datacenters have links to you.

MSN/LIVE.com

Owned by Microsoft, MSN and later Live.com is the third biggest search engine to the catering the occidental market. Thanks to the popular internet explorer msn search was extremely popular being the default search engine for the browser.

Unfortunately MSN/Live hasn’t been capable of competing with google and has lost most of its audience in recent years. Even so it is said that live.com users have always their credit cards on hand. This is because live.com clicks usually have a much higher conversion than google and yahoo.

Live.com shouldn’t be underrated. Ranking in MSN can still provide thousands of clicks. Ranking is mostly based on onsite optimization and as many backlinks as possible.