If you like using Google a lot (who doesn’t, really?), then you must know that there are various commands that you can use aside from simply entering keywords in the search box. These commands can help in narrowing down searches and getting more relevant results immediately. What might not be commonly known, however, is that many of the commands can be used for SEO purposes, more specifically, to analyze the performance of your web site.
One such command is the site: command. The syntax is very simple:
site:yourdomain
So, for example, you want to use this command for Smart PageRank, you need to key in
site:smartpagerank.com
Now that you know how to use that command, what is its use? Is it simply a cool thing to do or does it have implications for SEO? Of course it does!
One piece of information that you can find out from the results of a search of using this command is how much of your site is indexed. The idea behind this kind of search is that all or a large number of the pages in your web site should come up in the results. So, for example, if your web site has 300 pages and only 50 results show up, then that means there is a problem with the navigation. That means that Google is not seeing the other pages.
Naturally, you have to fix this problem. How can people find out about your other pages if they cannot be found by Google? Try optimizing your site map if you have one. Also, work on getting more inbound links to your other pages.
© 
[...] you are new to SEO, you might find yourself being lost with the various terms that you come across. In an effort to [...]
Well great command. I use it to check my site and found it that many of my site pages in not indexed my google. now I will have to work on it.
thanks for the great tips.