It covers all important concepts of NCERTs of three generations (1980s, 1990s and 2000s) which makes it an all in one holistic study material for preparing the theory. In each chapter NCERT concepts have been thoroughly explained with extra brainstorming points in separate boxes. Book is made informative with scientific column, fact file, funny corner and important dates. At the end of each chapter ?Exercise? section have been added which includes MCQs and Assertion & Reason questions for practice.