inform in English

<div dir="ltr" style="text-align: left;" trbidi="on"><div style="background: 0px 0px rgb(255, 255, 255); border: 0px; color: #666666; font-family: Arial, Helvetica, Verdana, sans-serif; line-height: 24px; outline: 0px; padding: 5px 0px; vertical-align: baseline;"><span style="font-size: large;">Search engines are <a href="http://www.webopedia.com/TERM/P/program.html" style="background: 0px 0px; border: 0px; color: #cc3300; margin: 0px; outline: 0px; padding: 0px; text-decoration: none; vertical-align: baseline;">programs</a> that search documents for specified <a href="http://www.webopedia.com/TERM/K/keyword.html" style="background: 0px 0px; border: 0px; color: #cc3300; margin: 0px; outline: 0px; padding: 0px; text-decoration: none; vertical-align: baseline;">keywords</a> and returns a list of the documents where the keywords were found. A <em style="background: 0px 0px; border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline;">search engine</em> 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 <a href="http://www.webopedia.com/TERM/W/World_Wide_Web.html" style="background: 0px 0px; border: 0px; color: #cc3300; margin: 0px; outline: 0px; padding: 0px; text-decoration: none; vertical-align: baseline;">World Wide Web.</a></span></div><h2 style="background: 0px 0px rgb(255, 255, 255); border: 0px; font-family: arial, helvetica, tahoma, verdana, sans-serif; font-size: 20px; font-stretch: normal; font-style: italic; line-height: normal; margin: 10px 0px 1px; outline: 0px; padding: 0px; vertical-align: baseline;">Web Search Engines</h2><div style="background: 0px 0px rgb(255, 255, 255); border: 0px; color: #666666; font-family: Arial, Helvetica, Verdana, sans-serif; line-height: 24px; outline: 0px; padding: 5px 0px; vertical-align: baseline;"><span style="font-size: large;">Typically, Web search engines work by sending out a <a href="http://www.webopedia.com/TERM/S/spider.html" style="background: 0px 0px; border: 0px; color: #cc3300; margin: 0px; outline: 0px; padding: 0px; text-decoration: none; vertical-align: baseline;"><em style="background: 0px 0px; border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline;">spider</em></a> to fetch as many documents as possible. Another program, called an <em style="background: 0px 0px; border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline;">indexer,</em> then reads these documents and creates an <a href="http://www.webopedia.com/TERM/I/index.html" style="background: 0px 0px; border: 0px; color: #cc3300; margin: 0px; outline: 0px; padding: 0px; text-decoration: none; vertical-align: baseline;">index</a> based on the words contained in each document. Each search engine uses a <a href="http://www.webopedia.com/TERM/P/proprietary.html" style="background: 0px 0px; border: 0px; color: #cc3300; margin: 0px; outline: 0px; padding: 0px; text-decoration: none; vertical-align: baseline;">proprietary</a> <a href="http://www.webopedia.com/TERM/A/algorithm.html" style="background: 0px 0px; border: 0px; color: #cc3300; margin: 0px; outline: 0px; padding: 0px; text-decoration: none; vertical-align: baseline;">algorithm</a> to create its indices such that, ideally, only meaningful results are returned for each <a href="http://www.webopedia.com/TERM/Q/query.html" style="background: 0px 0px; border: 0px; color: #cc3300; margin: 0px; outline: 0px; padding: 0px; text-decoration: none; vertical-align: baseline;"><em style="background: 0px 0px; border: 0px; margin: 0px; outline: 0px; padding: 0px; vertical-align: baseline;">query</em></a>.</span></div><div style="background: 0px 0px rgb(255, 255, 255); border: 0px; color: #666666; font-family: Arial, Helvetica, Verdana, sans-serif; line-height: 24px; outline: 0px; padding: 5px 0px; vertical-align: baseline;"><span style="font-size: large;">As many website owners rely on search engines to send traffic to their website, and entire industry has grown around the idea of optimizing Web content to improve your placement in search engine results. Learn more about <a href="http://www.webopedia.com/TERM/S/SEO.html" style="background: 0px 0px; border: 0px; color: #cc3300; margin: 0px; outline: 0px; padding: 0px; text-decoration: none; vertical-align: baseline;">search engine optimization (SEO)</a> in this Webopedia' definition.</span></div></div>

search engine

Search engines are programs that search documents for specified keywords and returns a list of the documents where the keywords were fou...