...............Google Bot is a search bot used by google .
Now what is a Search Bot ???
............ A Searchbot is your own personal search robot , which searches all the better sites on behalf of the creator , i mean yourself . You have to build a searchbot with your desired properties such as Colors , Tags , Locations , even Moods etc . Finally get instant Reports from your searchbot you have created . Cool ... ! Find more info at www.searchbots.net

Back to GoogleBot !
It collects all the resources from the net to build a searchable index for the Google search engine. Googlebot will crawling all or part of your site , if you have one . Googlebot finds pages by harvesting all of the links on every page it finds. It then follows these links to other web pages. New web pages must be linked to from another known page on the web in order to be crawled and indexed . Some of the new sites may be missed when the bot cannot able to read the content of the site .

Restrict the information on your site :
............As a webmaster , you can prevent access or limit your informations for the bots . For doing so you need to create a robots.txt file .
Robots.txt ?
........This file provides restrictions to search engine robots (known as "bots") that crawl the web. These bots are automated, and before they access pages of a site, they check to see if a robots.txt file exists that prevents them from accessing certain pages.
.........You can create this robots.txt file by seeing this forum . You can allow and disallow the google bot from finding the information from your site .

Types of Google Bots ::
Googlebot : crawl pages from google web index and news index
Googlebot-Mobile : crawls pages for google mobile index
Googlebot-Image : crawls pages for google image index
Mediapartners-Google : crawls pages to determine AdSense content. Google uses this bot to crawl your site if you show AdSense ads on your site.
Adsbot-Google : crawls pages to measure AdWords landing page quality. Google uses this bot if you use Google AdWords to advertise your site.