Page Rank
Developed by Larry Page and Sergey Brin of Google fame, PageRank is an indication of an individual page's importance relative to others on the world wide web. The basic principle that is used in the PageRank formula assumes that pages on the web have some inherent level of importance and that the link structure of the web could help to point out pages with greater and lesser value.
When many pages link to a page, that page earns a significant quantity of PageRank, basically determined by the raw quantity of global link popularity ascribed to that page. You can improve your PageRank by getting more links from both your own website (internal links) and other websites (external links).
We've discussed how links to your website is seen as votes for your site, the value of said votes being determined by the importance of the pages casting those votes by linking to your website. The higher the PageRank of these pages, the more value links carry. Hence pages with high PageRank linking to your pages confer more authority (and a resultant higher PageRank), to your site, because the search engine sees a link from an important page as an extention of that page's authority, according more importance to your page.
Initially one can focus on merely amassing as many links as possible, as a page with a large amount of links can still rank remarkably well in Google and Yahoo!, even if the sources aren't particularly relevant and the keywords are hardly used. However it is recommended to opt for quality rather than quantity as your website ages and grows. Growing your PageRank requires both link building and intelligent on page optimization to ensure that the flow of web traffic is directed through to the right places.
Next time we will look at how to get the most out of your link building efforts through Link Buiding Tips