The subject of Object-Oriented Programming is of prime importance for the students of Computer science and TI. Most of the projects are being implemented using Object Oriented Programming since it has the capability to manage the scale and complexity. Since this subject is of practical nature, it requires a thorough understanding of the basic concepts of the subject before putting them into practice. Therefore, keeping in mind the skills required for 21s Century, while writing the book, a special emphasis is laid on the following aspects: o Designed keeping in mind the objectives of NATIONAL EDUCATIONAL POLICY-2020 and OUTCOME BASED EDUCTION O Simple and lucid language enables even an average reader to grasp the fundamental concepts of the subject. o Numerous illustrative examples demonstrate the application of the concepts. o Numerous review and programming exercises for assessments as per BLOOM'S TAXONOMY. o Multiple choice questions (MCQs) provide an opportunity for self-assessment of the fundamental concepts learned. o Frequently asked questions (FAQs) to conquer the technical round of the CAMPUS PLACEMENT PROCESS with flying colors. o Lab Manual is provided to guide the students in handling their laboratory work, Enjoy reading this book, and feel free to send your free and frank comments, suggestions, and positive criticism. Your valuable input will help me to improve and fine-tune the book to meet your expectations.