Using which terms the Google PR is calculated? Does back links only matter in PR calculation or any other terms included in?
PR depends on dofollow backlinks. Backlink from other sites, also effect from links from other pages of the same site.
The first 10 sites with highest traffic are PR10 The next 100 have PR9 The next 1000 have PR8 The next 10,000 have PR7 and so on... At least that's when the PR was born...