Computer in action, a series of eight books, is our humble effort to provide, comprehensive learning and understanding of computer Science. The concepts have been presented in a lucid and student-friendly manner. The book aids students’ Learning with the help of variety of pedagogical elements which are in perfect sync with learning objectives. In addition to this, the book is supplemented with an access to active app (a web-based learning solution). It provides an amalgamation of traditional teaching approach with digital exposure giving an experiential learning journey to students.