This book is based on ten years of experience in training for novice testers. During this time, a huge collection of questions from listeners has accumulated, and problems and difficulties typical of many beginners have become clearly visible. It seems reasonable to summarize this material in the form of a book that will help novice testers to quickly immerse themselves in the profession and avoid many siege mistakes. Since the first edition, many edits have been made to the book based on reader feedback and the author's rethinking of individual ideas and formulations. Thanks to questions from readers and discussions at the trainings, it was possible to clarify and smooth out controversial issues, clarify definitions and give explanations where it turned out to be necessary. The ideal is unattainable, but I want to believe that a big step has been taken in its direction.