PageRank is an algorithm which analyses the relative 'weight' of a range of documents. Devised by Larry Page, it is a key factor in Google's search page result rankings. If nothing else it is a good guide for how well your website is doing (in Google's eyes) - the higher the pagerank, the more likely you are to appear in a search engine's results page. PageRank mathematically awards a score to each page based on the pages that link to it - both in terms of the number of pages linking to it, and importantly the relative weighting of the linking pages - a link from an 'important' page, counts more than a link from an 'unimportant' page.

Therefore, PageRank is reliant on the democratic nature of the web - if you think my page is good, then you'll link to it, and if I think your page is good I'll link to yours, but it should be stressed it is only one factor in Google's search engine rankings.

The PageRank algorithm is actually quite complicated, but for simplicity, a page's rank is split equally between the pages that it links to - i.e. if I have a PageRank 4, and I link to 4 pages, then each of those pages will receive 1 PageRank from me - which is then added to the PageRanks received from other links. As mentioned it isn't as simple as that, as there is a dampening factor to gradually reduce the weight of each link - normally around 0.85.

So what does PageRank mean for a website developer? Well, obviously you want a higher PageRank, so in turn this highlights the importance of gaining links from high quality sites - hence why many SEO strategies revolve around this.