tell me about google crawler.how much they are. when they crawl a web.is there any difference between crawler ,spider and robot.thanks in advance for the reply.
so GoogleCrawl is a kind of robot designed byGoogle to check all the websites, backlinks, content, tags and other things. It’salso used to make the searching results more efficient and more optimized for allthe users.
Every search engines has their own specially coded programs known as the "crawlers". The crawler of google is called as the "spider". Their are no differences between crawler, spider and robot since all of them are crawling the web. These crawlers are responsible for checking or indexing a website so that it will gain popularity both online or through users.
On the Webmaster Tools Home page, click the site you want. On the Dashboard, under Health, click Fetch as Google. In the text box, type the path to the page you want to check. In the dropdown list, select Web. (You can select another type of page, but currently we only accept submissions for our Web Search index.) Click Fetch. Google will fetch the URL you requested. It may take up to 10 or 15 minutes for Fetch status to be updated. Once you see a Fetch status of "Successful", click Submit to Index, and then click one of the following: To submit the individual URL to Google's index, select URL and click Submit. You can submit up to 500 URLs a week in this way. To submit the URL and all pages linked from it, click URL and all linked pages. You can submit up to 10 of these requests a month.
Google bot is a crawler which crawls the web while someone search for something. Each search engine has it's own crawler with different names. Every search engine's crawler is a bit different with everyone else. Search engine spider and search engine bots are same thing.