This paper defined e-learning and its development. The key terms and concepts of the teaching process were explained. An insight into the E-School project showed the state of affairs in the Republic of Croatia with regard to the digital maturity of schools and the introduction of digital textbooks and materials in schools. In this context, the new Curriculum for the subject of informatics, which has been in force since 2018, was also mentioned. The functionality of digital textbooks was presented through the presentation and explanation of the Law on Textbooks, the Rulebook on Textbook Standards and the CARNET Recommendation for the creation of digital educational content. Furthermore, the concept of digital textbooks was defined and their characteristics were stated. At the end of the theoretical part of the paper, an overview of scientific research related to the use of digital textbooks in teaching was given. In the second part of the paper, a qualitative analysis of textbooks for the 5th grade of primary school was carried out by three publishers: SysPrint, Profil Klett and Školske knjige. In the textbooks, the E-society domain was analyzed according to the criteria of the Textbook Standard: scientific, pedagogical and psychological, didactic-methodical, ethical, linguistic, artistic-graphic and technical. At the end, the textbooks were compared with regard to the mentioned characteristics and it was shown what individual publishers prioritize when creating digital textbooks.