PageRank explained?

Each time I do about about Google and/or PageRank, I feel as though I have not gone into enough depth. I cannot gauge how much or how little a reader might already know, and it seems to me, with the confusion surrounding these two mystical entities, that some background might be helpful...
Pagerank was originally developed at Stanford University by Larry Page later aided by Sergey Brin. Most people think (myself included) on first hearing the term, that the 'page' part of it refers to a web page whereas in fact this refers to it's originator.
The concept behind pagerank is to predict the likelihood of a random click on an internet link finding a specific URL. This is determined by the amount of links pointing to the specific URL, and also the perceived 'quality' of that link. The point of the exercise was to develop a search engine, and Google emerged from this project in 1998.
Pagerank 'compares' pages on the worldwide web, so ranking is always relative, rather than absolute, ranking is dynamic changing each time new pages are added to the web or new links are added to pages.
Via search 'bots' (small programs 'sent' out to crawl the web), a link can be examined and the originator page of that link is also assessed. If the originator page is weighted under the Pagerank system, the page it points to benefits from that weighting. All links are taken into account and a value is eventually assigned between 0 and 10. The hysteresis used for this weighting is always a closely guarded secret, and the precise calculation is always subject to 'tweaking' as new trends come and go.
In order for a page to receive a ranking, it must at least be linked to another page that is already visited by the 'bots' otherwise they will never 'find' it...Hence the quickest way to get a rank is not to submit your site to Google, but simply get a link from another page (preferably one that is visted frequently). The most popular and frequently updated sites are re-visited by these web crawlers several times a day, more static sites may not get a visit for weeks...
The last point I want to address is that YES Google uses PageRank to ascertain a SERP (Search engine results position) for given search keywords, but this is only one of a number of factors taken into account. This means that it is still possible for low Pageranked sites to get high search positions for their niche keywords.
I hope I have turned some fresh ground here, I am aiming NOT to be too repetitive, but feel free to leave a comment if you think I bang on too much about Google...