PageRank® is the fundamental algorithm on which Google’s rankings are based; however, it is no longer (and hasn’t been for a few years) the overwhelming factor in a page’s ability to rank. There are two types of PageRank®, one which Google uses internally and is a rational number between 0 and 1. The other is the public PageRank®, which is what used to show up on the Google Toolbar, but is now only accessible through third-party browser plugins or extensions, and is a number between 1 and 10. In both cases the higher the number the more ‘powerful’ the website.
A website’s PageRank® depends on the incoming links pointing to the website from external pages (either on the same site or third-party websites). Every link from another page acts as a vote or adds some amount of value to your page rank that’ll have an impact on rankings. The PageRank® of a web page is dependent only on link value and absolutely nothing else. The Google algorithm may decide to not assign the value of incoming links to a particular page; however, whatever value it does assign will be based on links, and not content or any other criteria.
Links are important to a website’s for ranking ability, it is an important aspect of search engine
optimization. Technically, the more incoming links a web page has the higher its PageRank® will be. Of course, the PageRank® of those pages linking to the site in question is also important–the higher the PageRank® of the linking page, the more value it can pass on to the site to which it is linking. But don’t go running after high PageRank® links yet; there is more to it than that.
Another important thing to note is that just cross-linking the pages of your own website will not increase your PageRank® (it will just pass it around from page to page).