"This glossary seeks to clarify key concepts relevant to data solidarity and explain data solidarity’s relationship to other key concepts and instruments in the domain of data governance and data ethics. It complements previous publications on this topic and in particular, the White Paper on Data Solidarity. Throughout, the glossary aims to indicate why data solidarity must become integral to data use in the health ecosystem. The first section of the glossary starts with a clarification of key terms that are central to the data solidarity approach. Section two then moves on to discuss key approaches to data governance. Section three introduces concepts that are related to data solidarity, either because of related practices or in that they may be confused with data solidarity. Our discussion of related concepts focuses both on a basic definition of these concepts and on clarifying their relation to data solidarity. Section four takes on ethical challenges and refers to important approaches that analyse the new dimensions of power and inequality that have emerged with digital transformations. Section five underlines key issues that can help move us forward and ends with a strong plea for a new concept of digital health citizenship." (About the glossary, page 4)