if molecules are closely packed together pressure increases and if it is released then pressure decreases..

If one layer of molecules is compressed pressure is created there and when it is released then it presses adjoining layer thus which in turn compresses the next layer..

it  goes so on and pressure is transmitted

BEST OF LUCK!!!!!!!!!!!!!!!!

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Dear vijay kumar pandey,

I recommend this book for complete concept clearance but remember thta this is for only reference for concept clarification !

The Feynman Lectures on Physics Volume 1 & Volume 2, By R.P. Feynman (Very nice book, all the fundamentals are well emphasized.)

Get your doubts very well cleared from this book !!

All the Best & Good Luck !!

Hope this helped you..!

If you loved the answer then please do not forget to approve it by clicking on "Yes" below..!

Dear Vijay Kumar Pandey,

 I will suggest you to follow the following book----  The Feynman Lectures on Physics Volume 1 & Volume 2, By R.P. Feynman

       It's a good book, which will clear all your doubts!!!!!!

     Plz. approve my answer!!!!!! Don't forget!!!!! Plz. Plz. Plz.!!!!!!!!!!

 Best Of Luck!!!!!