1) Big-name Web crawler 2) Web crawler 
Googlebot is the search bot software used by Google, which collects documents from the web to build a searchable index for the Google Search engine. If a webmaster wishes to restrict the information on their site available to a Googlebot, or another well-behaved spider, they can do so with the appropriate directives in a robots.txt file, or by add...
the crawler Google uses on a daily basis to find and index new web pages.
The spider program used by Google.