Simply you can refer to it as Google's view about the popularity and relevancy of your web pages. It's not limited to your root domain or homepage, but applies for each and every web page. Else it might have called, DomainRank or such, right? ;) Yeah, each web page has a PageRank which measures in a scale of 0 to 10, but generally we are interested in the PageRank of the root domain. Haven't check yours? Check it now.
Now you have a very basic idea about the PageRank. Here my intention is focused on discussing some details about Google PageRank including some misconceptions, but not to teach you how to calculate PageRank by yourself. You don't need to. You can have an idea about the mathematical algorithm behind PageRank from many different online sources including Wikipedia.
Let's start exploring :) I hope you will get to know more about Google PageRank as you go through.
No Google, No PageRank
The PageRank is determined by Google and if you explore other popular search engines such as Yahoo, Bing, your Google PageRank is not a crucial factor for them to determine importance of your web pages to rank them in their search results. The reason I wanna address it here 'cause people might fall into the misconception that PageRank is on top of all the web search engines.
Content vs Backlinks
Google PageRank is an algorithm based on facts and calculation is mostly an automated process by now. The popularity is determined by evaluating the backlinks aka inbound links pointing to your web pages, not by reading through your content.
You can look at a web page and find its content very helpful to you. Might be a life saver and you would recommend it to anyone and everyone. But Google doesn't take it that way. Your content won't taken into account in this algorithm. That could be wrong if did, as quality is intangible to be measured by just facts. Don't you think?
Google counts backlinks as mentions of your content across the web and measure importance. Let's think ~ If your content has been mentioned across the web on many different blogs / websites and linked back, isn't it convincing that your page has very interesting information for many others to talk about?
Google assumes, if more people link back and talking about a specific page, it has very helpful content and it will get a higher PageRank compared to other pages rarely mentioned across the web.
More Backlinks, Higher PageRank?
Could be. But it's not only about the quantity or how many referring to your web pages. There is a weight for each backlink pointing to your web pages depends on where they come from and how relevant they are.
You might have same amount of backlinks as your competitor, but if your competitor has backlinks coming from very popular websites, then they might have a higher PageRank. How about being mentioned in a popular and trusted news websites such as BBC or CNN? ;) Now again think about being mentioned in a PORN website.
Backlinks from popular sources where they have higher PageRank, will possibly help you to gain a higher PageRank.
It's a kind of rewarding for content that people find important to talk and link back. It's about earning it instead of gaining it.
But we can see people looking out for instant SEO boost and go for automated quality backlink generators, quality websites to spam with their links and working on trading links with sites that have higher PageRank, instead of generating and promoting the quality content that everyone wanna talk about. Here you can see how people can be abusive sometimes, especially when it comes to business perspectives :)
A reason why Google not depend on popularity alone but consider relevancy of backlinks which is not easier to automate.
Higher PageRank = Higher Search Engine Result Page (SERP) Rank?
What is your ultimate goal in SEO - Having a higher PageRank or improve the visibility of your pages on Google search?
PageRank and SERP Rank are related. But SERP is not totally based on PageRank. PageRank is only one signal that Google consider when ranking your content on Google search results. We are aware of how our content performs at search results, so just don't work only on increasing PageRank, but pay attention on other factors too. Higher PageRank doesn't ensure being on first few pages of Google search results. Not always.
When you wanna search something on Google search, would you love to see results with higher PageRank or relevant to your query? ;)
PageRank? Not for Me
You might have been getting more than enough attention for your blog or website. But when it comes to PageRank, you may believe you don't need it at all. Absolutely, you don't wanna depend on it. But ignoring is not the best way to deal with. Be in alert about your PageRank 'cause eventhough you manage to produce quality content that most of others wanna talk about, external factors might affect on your PageRank. It would be a starting point to find possible threats online.
Obsess! Not Too Much
Would you start over or start to believe you are an epic fail? You don't need to. But you can think about what he's referring to and work on turning that bad review into an opportunity to improve.
As PageRank is Google's opinion after analyzing your backlinks, research what could be the possible causes to see a drop in your ranking or being stabilized for a long time while generating quality content. Could be low quality backlinks. Here's some few common causes for PageRank drop.
Do you feel PageRank is complicate enough to understand? BTW, What is your PageRank?