The relevance of early childhood education and care (ECEC) is widely acknowledged in many countries, the number of ECEC settings is expanding correspondingly. This trend reflects the tremendous learning potential during early childhood. Right from birth and during early childhood a variety of learning processes are initiated that foster agency, self-regulation and development. Even the newborn is an active learner, a competent interaction partner and a problem-solver. In line with a deeper understanding of the mechanisms, principles and conditions of learning, early childhood education relies on pedagogical concepts, approaches and didactic methods that promote early learning and development. ECEC settings for young children stimulate exploration and action in everyday situations, embedded in social relations and interactions with peers and with a skilled and reliable pedagogical professional. The expansion and professionalization of the ECEC sector requires establishing a research infrastructure as well as implementing different research approaches at the micro-, meso- and macro-level of the system of early childhood education.