The goal of the search engines is to provide the most relevant information to its users. It's in the best interests of the search engines to be relevant because if the information returned is not relevant, the web user will use a different search engine and this will take money out of their (massive) pockets.
The majority of searches worldwide are conducted on 3 major search engines (Google, Yahoo! and MSN).
Are you familiar with algebra? The search engines use mathematical formulas called 'algorithms' to evaluate your website's relevance in relation to 'search terms' or 'keywords'. Each search engine uses different algorithms (which are not disclosed to the public), which focus on 2 main areas which I call: Content and Link Popularity.
The term 'link popularity' as I refer to it, means: "How authoritative your website is in the eyes of the search engines according to the amount of links you have and the quality and relevance of those links." (When compared to the content on your website and your competitors' websites).
This means any content in your website including: all text, images, audio and videos.
PageRank is a series of algorithms that was invented by Serge Brin and Larry Page, (the billionaire founders of Google) in 1998 and is constantly evolving.
Google's description of Pagerank:
"PageRank relies on the uniquely democratic nature of the web by using its vast link structure as an indicator of an individual page's value. Google interprets a link from page A to page B as a vote, by page A, for page B. But, Google looks at more than the sheer volume of votes or links a page receives, it also analyzes the pages that casts the vote. Votes cast by pages that are themselves 'important' weigh more heavily and help to make other pages 'important'."
PageRank (from here on I will refer to it as PR) works on a scale from 0 - 10, with 0 being lowest and 10 being highest. The higher your PR is, the more authoritative your site is.
Each website that links to you will give you some of their PR (if they have any) and vice versa. A great analogy is that PR is like water. The higher the PR of the website that links to you, the more water that they will give you. It's important to remember though that if that webpage is already giving water (linking) to lots of other sites, they will not give you as much as they would if they weren't linking to so many sites.
Most websites have the highest PR on their homepage because that's where the majority of their incoming links point to. A common theme is that a website will have a high PR on their homepage, but low or no PR on most of their internal pages.
It is important to have "deep links", these are links going to a page in your site other than your homepage.
Do I need to have a high PR to get into the top listings of the search engines?
That's a tricky question, my answer is Yes and No! Each of the search engines has different criteria when it comes to listing your website on their first page. It is possible that you could have PR of zero and get the first listing. However, this would most likely be only on a keyword with no competition. Example: "vanilla carrot croisants" Obviously this is not a word that anyone is typing into the search engines, (as of now lol).
If the keyword you are trying to get high rankings on is competitive, usually the top spots go to relevant sites that have the highest PR.
As the PageRank formula is an algorithm, how many links would it take from a PR 4 site webpage to equal one link from a PR5 site?
The answer to this is kept top secret by Google and Yahoo, but some industry experts predict that you would need between 8-10. So if that is true than it would take from 60-100 PR3 links to equal just 1 PR5 link based on PR alone.
Personally I think this is just a vague guideline that doesn't hold true in many cases. A PR5 link will be more or less valuable depending on: how many pages it is already linking to, it's relevance to your website theme, and other hidden factors.
How do I get onto the first page of Google?
Getting onto the first page of Google (and the other search engines) for a particular keyword or keyword phrase depends on 3 factors:
*Content - what your webpage contents say that it is about in relation to a particular keyword.
*Link Reputation - what other web-pages say your webpage is about (based on the words in and around the links that point to your website) and the determined quality and authority of those web-pages.
*Authority - how important your website is in the "eyes" of the search engines based on the amount of links and quality of links pointing to your site (PageRank)
The position that your site will get depends on the 'score' that it receives based on these factors. Remember that this 'score' is always in relation to a particular keyword.
If your website is about "chocolate cake recipes" (are you getting hungry yet?), your website can achieve rankings related to this keyword. You won't be able to rank for "banana pudding" or "creme brule" unless you have that content in your website.
If you would like to get higher search engine rankings I suggest you start to learn about how to optimize your content and how to get quality links to your site. Happy Optimizing!