This book is aimed at GCSE students. It provides comprehensive yet concise coverage of all the topics covered in the new AQA 8525 Computer Science specification, written and presented in a way that is accessible to teenagers. It will be invaluable both as a course text and as a revision guide for students nearing the end of their course. It is divided into nine sections covering every element of the specification. Sections 1, 2A and 2B of the textbook cover algorithms and programming concepts with a theoretical approach to provide students with experience of writing, tracing and debugging pseudocode solutions without the aid of a computer. These sections would complement practical programming experience.