Caching- Google take a snapshot of your website when it last visited and stored the data in case your website went down or if there are some any other issues.
Crawling- is the process of an engine requesting and successfully downloading a unique/new URL. Obstacles to crawling include no links to a URL, server downtime, robots exclusion, or using links from which bots cannot find a valid URL.
Thanks and Regards
This post has been edited by Richard Smith: Dec 4 2012, 02:11 PM