In this chapter, we discuss curation as a concept and practices of curating in relation to libraries, archives, and museums. The concept of curating collections may seem primarily connected to museums and exhibitions, especially as it invokes the practice of selecting and presenting objects to the public. However, traditional notions of curation also involve what happens with collection items before they reach the public (if anything). Thus, we distinguish between two senses of curation here, referring to the caretaker curator and the exhibition curator as broad typologies that help us to see what professionals in libraries, archives, and museums actually do with collections. The chapter presents discussions on the development of curating practices across the three sectors, connecting historical strands with current developments. Not least, we discuss how digitalization and the so-called “participatory turn” have changed and challenged practices of curation.