e-world, a series of eight books, is a humble effort to provide comprehensive learning and understanding of basic concepts and applications of computers. Based on the National Curriculum Framework (2005) and the CCE approach, the books have been written keeping in mind the feedback received during more than a decade of experience in teaching and interacting with the students. Interspersed with illustrations, tips and interesting facts, the concepts have been presented in a lucid and student-friendly manner.