During 2021 the Swedish government released a public inquiry with the purpose of strengthening the school library, to achieve this one of the propositions was to implement the concept media and information literacy into the curriculum. Today it's stated that a school librarian shall work towards strengthening the student’s digital literacy, this is the reason why this concept is used in this thesis. The aim of this study is to gain new knowledge regarding school librarians understanding of the concept digital literacy, how they describe their prerequisites and how they legitimize their work based on their profession. The data was collected by conducting semi-structured interviews with five high school librarians. The data was then analyzed using qualitative content analysis. The theoretical framework used in this study was profession theory and new institutional theory. The outcome of the interviews showed that a high school librarian prefers the use of media and information literacy comparative to digital literacy because it describes their qualification more clearly. The conclusion reached was that the governing documents released by the state gives the high school librarian legitimacy and prerequisite in their educational work, this is the reason why interpretations of concepts become significant for their profession.