If you're involved in SEO, or have the Google Toolbar installed in your browser, chances are you'll have come across Google PageRank.

It's basically a score for your website out of 10 based upon how important Google think you're page is in the whole scheme of interweb searchery.

By important, Google means how many people link to your page, the more pages there are, the more relevant your page must be.  But that's not quite it, it's no good having thousands of links to your page if they're not important pages themselves, so in turn, it is also determined by the quality of the pages that link to you.

Google themselves say the importance is made up of over 500 million variables and 2 billion terms, whilst Wikipedia have a "simplified" algorithm that in my opinion is anything but,  mind you, maths was never my forte.

In a nutshell, more quality links = higher page ranks.  Like with many SEO techniques, PageRank alone will not guarantee you a high ranking, but it will help, it's more than likely that pages with a lower PageRank will appear above yours if they have managed to crack other areas of SEO.

Rest assured though, if you have a number of quality links to your page, it's SERP ranking will improve along with it's PageRank, which will do you no harm at all in the SEO world.

Realistically speaking, as a webmaster of an SME you should probably be aiming for a score of around 4 or 5 once you're site is established in the SERPs.  High scores of 7 or above to be reserved for the big players, such as Microsoft, BBC and Google themselves (the google home page gets 8) whilst Adobe is the only ranking of 10 I've come across on my travels.  If there are anymore 10s out there, I'd be interested to know where they are.