How Google Crawl and Save Website?

Google stores all things in its database. It crawls site four times in a year with three months time periods.It started with January month.

Data is crawled through spiders, but I don't know which technique is used to make a spider.

Thanks Paulwalker. your answer is really useful and there are new information for me.

Google stores all things in its database. It crawls site four times in a year with three months time periods.It started with January month.

Hi,

1. I think search engine bots would crawl sites more frequently but not only four times, especially on those hot(high PR) sites.
2. Of course, search engines would save all data bots fetch in their database and rank them according to their own algorithm.

all the best,

google has a very big database to save site and uses spiders/crawlers to cache the site

Every time Google Bot finds new data on any website it crawls and index/re index that website.

I think you are talking about the google Cache. It takes images and saves them, so that the searchers can also view it sometime after even if the website has been closed!