The development of technology has significantly changed in the last 50 years, and the media are becoming a part of children's everyday life since birth. This is increasingly encouraging professionals to conduct new research to further examine the effects of technology on child development. However, despite numerous researches, it is still impossible to say unanimously whether the media leave a positive or negative impact on our lives. But in any case, the most vulnerable group are children whose brains are not yet fully developed. For this reason, most research does not recommend exposing children to screens at least before 18 months of age (with the exception of video calls), and it is important for all ages to limit time and control content. Media content does not affect all children equally, but the impact largely depends on the characteristics of the child, his environment, parenting style and the amount of time he spends in front of the screens. The importance of media education from preschool age is emphasized in order to teach children to use the media independently and to develop a critical attitude towards media content. The aim of this graduate thesis is to present the media, their ubiquity in the lives of children and a detailed review of the literature to point out the latest recommendations and guidelines to avoid the unintended consequences of the media.