This book was created to serve as an educational aid for teaching the Informatics course of the Orientation Group of Economics and Informatics Studies for the third grade of the General Unified Lyceum and is intended for both students and teachers.

It is an attempt to write a new type of manual, more functional, where all the answers are recorded directly on it, in special answer forms. It is, therefore, a workbook, which will serve as a supplementary tool in teaching the course. The exercise statements follow the standards of the Panhellenic Examinations and according to the new curriculum of the Ministry.

The structure of the book is as follows:

The book consists of two parts:

Part A: Includes the required material per section in the form of questions and answers. Each definition and command syntax is referred to with special symbols, making it easy for the reader to search for what they want and locate it immediately.

Part B: Exercises & solution methods

The material is divided into 12 Sections to present it as effectively as possible. In some places, the presentation of the material follows a different path from the usual, as it has been observed that it facilitates the student's understanding of the concepts.
Each section (with exceptions) consists of 3 groups of exercises:
    ▪ Group A: Comprehension questions
    ▪ Group B: Theoretical exercises
    ▪ Group C: Programming exercises
    Exercises considered to be of increased difficulty carry a special marking (*).

A large part of the book is occupied by detailed methodology, where each method is described in great detail with free text, schematic algorithm, and code in GLOSSA.
At the end of the book, there is a special Appendix with six (6) specially designed informatics labs.