Search Engine

Hello, today I am going to talk about search engines. First of all, what is it?

Search engines are programs that search documents for specified keywords and returns a list of the documents where the keywords were found. A search engine is really a general class of programs, however, the term is often used to specifically describe systems like Google, Bing and Yahoo! Search that enable users to search for documents on the World Wide Web.

The world's most popular search engine is GOOGLE. 

Google is fast, relevant, and the largest single catalogue of Web pages available today. Make sure you try the Google 'images', 'maps' and 'news' features.

Google's search engine crawler, called the GoogleBot, travels from Web page to Web page following hyperlinks. When a new page is found, Googlebot will also crawl all the hyperlinks on that page as well. A second bot also crawls indexed pages to keep the index updated. As pages are indexed, they are also given scores based on criteria like how many times words are displayed (density), link popularity, HTML code, themes, content (the text) and more. These scores are what determines where the Web page listing appears in the search results. The link for this search engine is:  http://www.google.com/

Bing

Bing is a new search engine from Microsoft. Microsoft calls it a "Decision Engine," because it's designed to return search results in a format that organizes answers to address your needs. When you search on Bing, in addition to providing relevant search results, the search engine also shows a list of related searches on the left-hand side of the search engine results page . You can also access a quick link to see recent search history. Bing uses technology from a company called Powerset, which Microsoft acquired.

Bing launched with several features that are unique in the search market. For example, when you mouse-over a Bing result a small pop-up provides additional information for that result, including a contact e-mail address if available. The main search box features suggestions as you type, and Bing's travel search is touted as being the best on the net. Bing is expected to replace Microsoft Live Search.
Web Link: http://www.bing.com/

Yahoo

The Yahoo Search index is made up of billions of Web pages, which are populated by a Web crawler. When Yahoo crawls pages it takes several factors into consideration. The search terms included in the page's Title and Description tag, page content (the text), keyword density, inbound hyperlinks and so on. Yahoo has also started using page rank technologies and also takes Yahoo Directory listings and paid inclusions into consideration when indexing and ranking pages. Users can submit their own pagesdirectly to the Yahoo Search index and the Yahoo Directory, and also submit products for inclusion in Yahoo Shopping. Yahoo has also incorporated special search and services such as Webmail, Local, video, images, shopping and news search products.
Web Link: 
http://www.yahoo.com/

Windows Live Search

Microsoft's search engine, Windows Live Search offers a huge improvement over MSN Search and is also integrated into Microsoft's Live.com. When it launched September 12, 2006, it was a new search engine built from scratch using a new algorithmic engine that was integrated throughout Windows Live and MSN. Some of the features of Windows Live Search include a nice feature-rich interface — something new and unique in the Web search space. By signing in to a personalized Live search you can add feeds and subscribe to search results. Windows Live Search also incorporates specific searches for images, news, academic journals, RSS feeds, maps and mor

http://www.livesearch.com/

Ask.com

Ask.com was first launched in 1997, but founded in 1996 in Berkeley, Calif. by David Warthen, CTO and veteran software developer, and Garrett Gruener. Originally Ask.com was called Ask Jeeves and was designed to enable users to provide direct answers to questions, but also supported keyword searching as well. From 1997 to 2000, Ask.com launched a kids version (AJKids) and also launched several international versions of the popular question-based search engine. In 2000, a related search feature and an online shopping advisor channel was added to Ask Jeeves. One of the major technology changes took place over the next two years when Ask Jeeves acquired Teoma Technologies and then integrated the Teoma algorithmic search technology into Ask Jeeves.
http://es.ask.com/