yagyashree:
Please note that this forum is ONLY for accessibility questions for the physically challenged.
If you reply to questions here, please do NOT answer questions which have nothing to do with the physically challenged.
(I will delete them as soon as I see them so you are wasting your time in any case, but answering them here encourages more people to post way off-topic posts here.)
P.S. An answer of "i searched but i cann't find any public article for your explanation?" isn't any use to the poster of this question. If you haven't an answer, don't reply!
WSS FAQ sites:
http://wssv2faq.mindsharp.com and
http://wssv3faq.mindsharp.com Total list of WSS 3.0 / MOSS 2007 Books (including foreign language)
http://wssv3faq.mindsharp.com/Lists/v3%20WSS%20FAQ/V%20Books.aspx