In order to consider the relation between interest and curiosity, we first review various points of view on this issue, and discuss the scientific importance of making a distinction between the two concepts. Next, we explain that interest defined as a psychological state and as a cognitive and motivational variable can be supported to develop. Furthermore, the content-specific development of interest provides a different type of information search than curiosity, defined as the motivation to close a knowledge gap driven by uncertainty. We also discuss how earlier and later phases of developing interest are related to curiosity. More specifically, we suggest that (a) once curiosity is resolved, it may not result in any further engagement, or it may trigger a situational interest that could develop, and (b) when an existing, more developed interest initiates, supports or is related to a particular instance of triggered curiosity, continued engagement (and information search) is likely. In concluding, we point to needed neuroscientific research that could contribute to further clarifying the relation between interest and curiosity. This information is as important to research, as it is to practice.