This book serves as a useful aid for the computer science course of the 9th grade. Its goal is to help you understand the basic concepts of computer science and to enrich your knowledge on contemporary topics related to it.

Specifically, this book contains:
- Basic theory questions
- Answers to all the questions, activities, and discussion topics of the school textbook
- Answers to the self-assessment exercises of the school textbook
- Consolidation exercises at the end of each chapter, to check if you have understood the key points of the lesson
- Additional activities and further discussion topics that will help you better understand the material
- Additional information

Christos Nikolaidis