This book aims at doing 2 things: first to provide the aspirants of UPSC CSE with a one stop solution to their most basic doubts and second to give them a solid foundation as they begin preparation. The idea of this book was mine but the execution was not mine alone. It required a lot of support and at times push from many people to finish the work. But if I were to dedicate this book it would surely be to two sets of people my family and the millions of aspirants. My family has always supported