You must understand that each page has a web site Page Rank. This dependent on so many factors including quality of content, number of backlinks and the huge traffic going to that page or your webste itself. People may normally use PR to mean Page Rank. It's still the same.
Page Rank are being updated like 3 to 4 times yearly depending on Google's initiative. The lower your rank simply means the higher the relevance of your website.
To check your own page rank visit: http://www.websiteoutlook.com and type your domain in the space bar or any website you wish to check out its page rank. You will then press 'Go' Results would be displayed within seconds. Also have in mind that you may not the updated information about the website you are checking, in this case just click on 'update' on the website and recheck again.