Introduction to Google Rating system
Google runs on a unique combination of advanced hardware and software. The
speed you experience can be attributed in part to the efficiency of the search
algorithm and partly to the thousands of low cost PC's networked together
to create a superfast search engine.
The heart of the Google software is PageRank™, a system for ranking web pages
developed by Google founders Larry Page and Sergey Brin at Stanford University.
And while Google have dozens of engineers working to improve every aspect of
Google on a daily basis, PageRank continues to provide the basis for all of the
web search tools.
PageRank
PageRank relies on the uniquely democratic nature of the web by using its vast
link structure as an indicator of an individual page's value. In essence,
Google interprets a link from page A to page B as a vote, by page A, for page
B. But, Google looks at more than the sheer volume of votes, or links a page
receives; it also analyzes the page that casts the vote. Votes cast by pages
that are themselves "important" weigh more heavily and help to make other pages
"important."
Important, high-quality sites receive a higher PageRank, which Google remembers
each time it conducts a search. Of course, important pages mean nothing to you
if they don't match your query. So, Google combines PageRank with sophisticated
text-matching techniques to find pages that are both important and relevant to
your search. Google goes far beyond the number of times a term appears on a
page and examines all aspects of the page's content (and the content of the
pages linking to it) to determine if it's a good match for your query.
Add Page Rank Google™ gadget displaying Page Rank for up to 10 sites:

To add the PageRank button follow the steps below:
1. Highlight the code in the text box below.
2. Copy the code (Ctrl+C or Command+C).
3. Open the page(s) that you want to add the PageRank button to with the editor
of your choice.
4. Paste the code into the page (Ctrl+V or Command+V) In the location you want
it.
5. Save your page.
6. Upload the page(s) to your web hosting account.
If you installed the PageRank button correctly, your PageRank will be
displayed.
NOTE: Editing the HTML code is not recommended. Doing so may cause the PageRank
button to not display correctly.