Web Search Engine

Web Search Engine

Definition of Web search engine :

A program that searches documents for specified keywords and returns a list of the documents where the keywords were found. Although search engine is really a general class of programs, the term is often used to specifically describe systems like Google, Alta Vista and Excite that enable users to search for documents on the World Wide Web and USENET newsgroups.
Typically, a search engine works by sending out a spider to fetch as many documents as possible. Another program, called an indexer, then reads these documents and creates an index based on the words contained in each document. Each search engine uses a proprietary algorithm to create its indices such that, ideally, only meaningful results are returned for each query.

Key Words     | How ethanol is made and where ethanol is used in alternative fuel     |
Search Engine     | Google www.google.com     | Yahoo www.yahoo.com     | Msn/Bing www.bing.com     |
Result     | 569,000 results     | 424,000 results     | 491,000 results     |
Collapsed pages from first 20 pages     | None     | 2 collapsed pages     | 2 collapsed pages     |
Speed       | Fast     | Normal     | Normal     |
Translator     | Available     | Unavailable     | Unavailable     |
Update     | Daily     | Daily     | Infrequently     |
Authorship/ Sponsorship     | Clearly stated     | Clearly stated     | Clearly stated     |
Languages       | 124 types     | 40 types     | 40 types     |

First 5 web pages from 3 search engine.

Search Engine     | Website     | Quality     |
    Google     | http://en.wikipedia.org/wiki/Ethanol_fuel     | Good     |
http://en.wikipedia.org/wiki/Biofuel     | Good     |
http://auto.howstuffworks.com/fuel-efficiency/alternative-fuels/question707.htm     | Normal     |
http://auto.howstuffworks.com/fuel-efficiency/alternative-fuels/ethanol-facts.htm     | Normal     |
http://e85.whipnet.net/ethanol.faq/make.ethanol.html     | Normal...