The purpose of this research was to characterize the curation activity of preservice teachers practicing digital curation by constructing "knowledge exhibitions" in an academic course. Our database included 64 knowledge exhibitions on the Scoop.it platform. Factor analysis of curator's activities resulted in 3 factors, contributing 57.63% of the total variance explained: the social factor, the personal content factor and the personal process factor. Narratives of curators' reflections were analyzed using content analysis, resulting in 3 additional categories: relevance, curator activities and products. When combining the qualitative and quantitative categories, a two-dimensional conceptual model was constructed. The model illustrates a taxonomy of components that are included in the curation process, which portrays authentic learning. We conclude that curation contributes to the improvement of students' knowledge and 21st skills as curators. Curation requires personal and social skills, e.g., cognitive and meta-cognitive skills from an individual and social perspective, social skills on social media and affective skills. Hence, while focusing on personal skills in constructing an ontology, curation is also social in nature. Using social curation transforms learning, but surprisingly is uncommon in educational settings, and research is consequently meager. This highlights the need for incorporating curation as authentic learning in teacher training.