Page Rank is the measure of importance Google assigns to a Web page on a scale of 1 to 10.
You can check the PageRank value of every page you visit by downloading the Google Toolbar.

Google’s founders, Sergey Brin and Larry Page, formulated a Search Engine algorithm that shifted the ranking weight to off-page factors. They developed a formula called PageRank, in which the algorithm counts the number of sites that link to a page and then assigns the page an importance score on a scale of 1-10. The higher the number and importance of sites that link to your page, the higher the PageRank of your Web site.

What is Link Popularity?
Link Popularity refers to the number of links pointing TO your site FROM other sites on the Web.
The Search Engines consider your site more important and rank it higher if several other sites link to your site.

Quality links means links from related pages and with high rankings in search engines.
Building Quality and Relevant back links is a dual advantage where you attract vistors from the reciprocal linking site and simultaneously boost your websites Page Rank.

Types of links
There are two types of links you can establish on the web.

Reciprocal links
Link exchange is an easier way to establish links from other websites to your website.
In link exchange process, you trade links with prospective partner sites by offering a link to their site from your own site.
This method is a fast way to establish several hundred links to your website. However, it may not get you great benefits.


One-way links
To establish ‘only-incoming’ links also called ‘one-way links’ or ‘Non-Reciprocal links’.
Only incoming links are the links established on the other websites where you do not need to link back to them.


There are various compelling reasons and methods to establish such one-way links which include linking back from a different website that you may own, publishing articles on sites, content syndication, listing in trade directories and giving out press releases in news networks.


Why links are so important
Now these days, inbounds links are the one of most important factor for getting a high keyword ranking, the most search engines are ranking their search result on the link popularity from your site.
Not the quantity from the links, but the quality of those links is important.

Click here download Google Page Rank tool through you can measure Page rank of a webpage.