Relevance and Importance: Relevance - when a user types in a query, Google finds all the documents in its index that contain the words from that query. Importance - After Google has fetched the relevant documents, it sorts them by importance.
Reason:- In order to avoid using a very long number to represent the PageRank of web pages, therefore Google has divided the Total PageRank into 10 ranges or 10 scales. This is called Google Toolbar PageRank
Real PR values are what Google actually uses in their algorithm, and these values are constantly changing.
Toolbar PR values are only updated every 3 - 4 months
When a page is created, PR from 0-1 can be easily acquired. However to raise the PR from 6 to 7 it is required by significantly more inbound links
Fig -1, Web pages which are well-linked, meaning every page has at least one inbound link and one outbound link. This allows the PageRank to "flow" through all the pages and achieve the maximum total Page Rank.
Fig-2, Web pages contains a dangling link, meaning it links to a page that doesn't link out to anything. A dangling link prevents the system from achieving its maximum total Page Rank because it stops the flow of Page Rank.
However, most websites have several important pages that deserve high rankings for relevant terms--not just the home page.
Page Rank value of a single page can be increased by adding more links to it.
A page accumulates Page Rank from its inbound links and distributes Page Rank evenly across its outbound links.
Subtract links from unimportant pages:
Google wants to rank pages that are independently valuable to Google's users. In other words, when a user types in a query, they are searching for something specific and Google wants to satisfy that user after one click.
If the important page is reached only after too many clicks the PR will be relatively lowered.
For example, if a user searches for iphone, Google wants to deliver Apple's page about iphones--not the Apple home page or their sitemap or any other page that would require the user to click unnecessarily.
The more pages you have on your site, the higher the maximum total Page Rank. When we talk about "adding a page," it is assumed that the new page will be valuable and index able, according to Google.
Page rank sculpting:
To redistribute PageRank to important pages, a process called PageRank sculpting.
The goal of PageRank sculpting is to increase our current search engine rankings by simply altering the crawlable linking structure of our site.
Indexing - Process where Google "reads" the content of your webpage and transforms it into a representation of content and processed for search results.
The process of indexing a webpage includes things like removing HTML code, determining keyword frequencies and assigning weighted values to certain terms (depending on how the terms appeared in the content).
If you include the noindex attribute in your page's robots Meta tag, you are basically telling Google not to consider that page relevant to any query, and therefore, not to list it in any search results.
Crawling - Process of a search engine identifying links in your content and recording them.
Google uses this information to discover new pages and to calculate PageRank.
Adding the nofollow attribute to the robots Meta tag will tell Google to ignore all the links on the page.
Caching- Google stores a local copy of your page on its own computers.
This copy is essentially a snapshot of your page's code
Webmasters who don't want Google to cache their page can add the noarchiveattribute to the robots Meta tag.
THANK YOU Submitted By Sudha http://sudhaseo.blogspot.com