Google page rank is a mathematical algorithm used by Google that reflects the importance of a webpage on a scale of 0 to 10 with 10 being the most important and 0 being put least important. This mathematical algorithm takes into account more than 500 million variables and 2 billion terms.
in recent months, Google has stated that Google page rank may have less impact on your SEO and Google ranking/position. Though, with 500 million different variables taken into account there is bound to be some overlap. For example, some overlap could include the age of your site and quality of sites that link back to your site.
Google page rank also has use in helping you determine the quality of the site that is linking back to yours and the quality of the sites you are doing business with.
When you link to other sites, you are casting a vote for that site with your Google PageRank. With more outbound links on your site, you are more Google Page Rank.
Your Google page rank well improve naturally over time as you develop your site and work with a reputable SEO.