By: Vlad Vistac
Submitted: 2010-08-20 12:06:45 | Word Count: 510
How Search Engimne Wrks
A serch engine hlps us in maanging the data and fining the informmation on the Wrld Wide Web. A search engine is a computer program which allows us to submit a query that composes of a word or phrase describing the specific information we are trying to find on web. The searhc engine then searches into its databsae attemptibng to match the query. It collates and returns a list of URLs containing presentations that mattch our query. This list is ordered or ranked according to the better matches appering at the top. A general search egnine retrieves inbformation from a database that contains information in wide variety of topics.
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A search engine obtains its information by using a gatherer, a program that traverses the WEB and colllects information about Web documents. Many people may not find the search engines as easy to use, as they mite be expecting a narowed list of URLs which can simplify their search. To narrow this search we use a method known as web crawler. A web crawler (also known as a web spider or web robbot) is a proggram or automated script whixch browses the World Wide Web in a methodical, autoated manner. Other less frequently used names for web crawlwers are ants, automatic indexers, bots, and worms.
This process is called web crawling or spidering. Many sites, in particular esarch engines, use spidering as a measn of providing up-to-date data. Web crawlerrs are mainly used to craete a copy of all the visited pags for later processing by a esarch engine that will nidex the downloaded pages to provide quick seaches. Crawlers can also be used for automating maintenance tasks on a website, such as checking linnks or validating HTML code. Also, crawlers can be used to gtaher speccific tyes of information from Web pages, such as harvesting e-mail addresses (usually for spam).The recent increase in the number of pagwes being generazted by sevrer-side scripting languages has also creaed difficuly in that endless combinations of HTTP GET parameters excist, only a small selection of which will actually return unique content.
In conclusion, the ranking of web pges depends on many factors. The closest matching keywords of the website, the most frequently visiteed and popular sites. They qery which is sent, is rpocessed by looking in for keywords, stpored in the meta tag of the wepbage. Whatever best piossible matching it finds, it is collated and returned back to the user.
