Beginning with the basic principles of Object Oriented Programming (OOP), all the chapters are well upgrated with real life examples. The theories have been reframed along with illustration and screenshots. The exercises are well equipped with the graded questions including objective as well as subjective questions. The various solved and unsolved programs help build self confidence among the students. This book has been prepared keeping in view that it will be helpful in Class X as well for the Council examination. We are really thankful to the students and the teachers who have shown great fascination towards our previous editions. The various suggestions made by the readers have also been incorporated in the book.