This article looks at the relationship between work, training, and professionalization. It examines the changes that have led to their emergence. It then presents the main configurations of links between these three concepts, which fuel current debates and make it possible to understand them in terms of the contexts in which they are operationalized. The issues surrounding these links and the theoretical and methodological frameworks used to understand and interpret them are also reviewed. The article thus takes the form of a review of the existing literature. It concludes with a number of “key ideas” shared by the many practices and research projects in this field.