With all the talk of SEO, SEM, SE... What is important, and what is not??? Google makes it a bit easier to rank yourself and find out, "What is your Google Juice?"
PageRank is a numeric value that represents how important a page is on the web. When one page links to another page, it is effectively casting a vote for the other page. The more votes , the more important the page must be. But, it is also important to realize that Google also measures the importance of the page that is casting the vote, so one vote can be of more “significance” then another. Google then uses all of this information to calcualte a PageRank or PR. A very technical analysis can be found at Wikipedia, Google, and WebWork Shop.
Why is it important? Read about Online Marketing - why its important, why you need to do it, and how you can do it now.