When you conduct a search on Google you aren’t searching the web. What you are actually searching is Google’s index of the web. You see Google can only index websites that are available to be found by search engine spiders. These spiders index all available websites by beginning at one website and then crawling from that website to any other sites it links with. Once a spider crawls to another site it indexes the content of that site and crawls away once more to others sites that are linked with it. Thus it is the connectivity of websites to one another that allows the Google spider bots to find available websites. This explains why having many inbound links is a major component of how well your website ranks among search engines, particularly Google.
Check out this 3 minute video presentation from an engineer in the quality group at Google, Matt Cutts, on “How Search Works.” A visual for this type of concept will greatly help your understanding.
What do you think? A little easier to understand with a cartoon animation?