A Web crawler is a computer program that browses the World Wide Web in a methodical, automated manner. Other terms for Web crawlers are ants, automatic indexers, bots, and worms[1] or Web spider, Web robot, or—especially in the FOAF community—Web scutter[2].

This process is called Web crawling or spidering. Many sites, in particular search engines, use spidering as a means of providing up-to-date data. Web crawlers are mainly used to create a copy of all the visited pages for later processing by a search engine that will index the downloaded pages to provide fast searches. Crawlers can also be used for automating maintenance tasks on a Web site, such as checking links or validating HTML code. Also, crawlers can be used to gather specific types of information from Web pages, such as harvesting e-mail addresses (usually for spam).

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London Hotel

A web crawler is a relatively simple, automated program, or script, that methodically scans or "crawls" through Internet pages to create an index of of the data it's looking for. Alternative names for a web crawler include web spider, web robot, bot, crawler and automatic indexer.

A web crawler can be used for many purposes. Probably the most common use associated with the term is related to search engines. Search engines use web crawlers to collect information about what is out there on public web pages. Their primary purpose is to collect data so that when Internet surfers enter a search term on their site, they can quickly provide the surfer with relevant web sites.

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acting auditions

Please stop copy pasting from Wikipedia because all know about it.

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seo link building services | on page SEO

ya you are right crawler is the auto serve search engine process which crawl your website automatically.