I need a knowledge about googles' custom search engine.
anybody can give me a lecture on this.

Sure, Google it!

Are you referring to this?
http://www.google.com/sitesearch/

Googles search engine is custom for everyone. If you are signed into your Google account, the searches will come up different than if you search from a new computer on a different IP well not signed in. Also the Google pluses make a difference as well.

Good grief!!!!!

banghead.gif banghead.gif

I will try to make this discussion meaningful by pointing out there are other alternatives to Google Site Search... If that is what the OP somehow wanted to discuss (comparison) then there is still hope... Because otherwise