We are living in an information age dependent upon computers. Computers have established themselves as the biggest innovation of mankind. The world of technology and computer systems is continually evolving, and has touched virtually every aspect of our lives. They have been paving the way for an exciting, challenging, adventurous, technological world. Computers have revolutionized the way we learn and communicate. The practical applications of technology and computer systems are extensive and always growing. Keeping this evolving computer world in mind we have prepared the series ENTER — A Complete Course In Computer Science for Classes 1 to 8. It is specially designed for providing a vast theoretical and practical knowledge of computers to the students. It is the most comprehensive series in which activity and tool based approach is incorporated. Each chapter in the series starts with an engaging introduction followed by an activity based approach to learning, which is supported with ample number of diagrams, pictures and relevant screenshots. The exercises in each chapter have sufficient practical and activity