What is WEB CRAWLER?

What does WEB CRAWLER mean? WEB CRAWLER meaning - WEB CRAWLER definition - WEB CRAWLER explanation. What is the meaning of WEB CRAWLER? What is the definition of WEB CRAWLER? What does WEB CRAWLER stand for? What is WEB CRAWLER meaning? What is WEB CRAWLER definition?

A Web crawler is an Internet bot which systematically browses the World Wide Web, typically for the purpose of Web indexing.

Web search engines and some other sites use Web crawling or spidering software to update their web content or indexes of others sites' web content. Web crawlers can copy all the pages they visit for later processing by a search engine which indexes the downloaded pages so the users can search much more efficiently.

Crawlers consume resources on the systems they visit and often visit sites without tacit approval. Issues of schedule, load, and "politeness" come into play when large collections of pages are accessed. Mechanisms exist for public sites not wishing to be crawled to make this known to the crawling agent.

As the number of pages on the internet is extremely large, even the largest crawlers fall short of making a complete index.

Crawlers can validate hyperlinks and HTML code. They can also be used for web scraping (see also data-driven programming).