I am new in seo field and not know more about it, so please share your review about robot.txt. what is this and how its important for seo result?
This question has been asked and answered many, many times before. Please read the [SEO FAQ or use the [url=http://www.sitepoint.com/forums/search.php]Search](http://www.sitepoint.com/forums/showthread.php?182915-FAQ-Search-Engine-Optimization) facility to find past discussions.
If, after reading those, you've still got any specific questions that haven't been answered, please do come back and start a new thread. In the meantime, I'm closing this one.