PageRank is Google’s measure of the importance of a web page. It is a numeric score assigned by Google and ranges from 0 to 10. Google uses the vast link structure of the web as an indicator of an individual page’s value. When one page links to another, it is effectively casting a vote for the other page. Google also analyzes the page that casts the vote. Votes received from pages that are themselves “important” carry more weight. Google combines PageRank with text-matching techniques to find web pages that are both important and relevant to search queries.
You can now check your Google PageRank without using the Google toolbar, check out http://www.mohanjith.net/pagerank/ .