This textbook provides comprehensive yet concise coverage of all the topics covered in the new AQA GCSE Computer Science Specification 8520, written in a clear and understandable style with many in-text questions to test students' understanding of the material and their ability to apply it. This will be invaluable not only as a course textbook but also as a revision guide. Each of the eight sections cover one of the major topics in specification sections 3.1 - 3.7 for Paper 1 and Paper 2 of this course. Each subtopic contains sample examination questions from past examination papers, which can be set as homework. Answers to all these are available to teachers only, in a Teachers Supplement which can be ordered free from our website as a downloadable pack. This book has been approved by AQA.