The 5 on the toolbar is your PageRank(TM). Is is a mathematical measure of:
1) The number of links to your page (
PR is based per page, not per site)
2) The PageRank of the pages that the links are from
3) The number of links that are on the page that the link is from
4) If Google knows about the link (the page is in Google index) and if the link is spiderable (eg not javascript)
PR is only one of >100 things that go into the ranking of a page in the search results.
The
PR on the toolbar is also only an estimate -
PR is actually on a log scale - so a
PR 5 could be 5.00001 (really close to a 4.9999 = PR4), but a long way from 5.9999.
The
PR on the toolbar is also no exactly accurate, as its behind the internal
PR updates that Googles does - they appear to be updating publically available
PR every month or so for the last few months.
To find how you rank for a keyword(s) - go to
www.google.com/ie (change preferences to 100 per page) and look for your site
CBP