E-world, a series of eight books, is a humble effort to provide comprehensive learning and understanding of basic concepts and applications of computers. The series conforms to the National Curriculum Framework (NCF) 2005 and the CCE approach. The books have been developed based on an extensive feedback received from teachers and authors’ experience of over a decade in teaching and interacting with students. Interspersed with illustrations, tips and interesting facts, the concepts have been presented in a lucid and student-friendly manner