Introduction: This paper considers the nature of information science as a discipline and profession. Method: It is based on conceptual analysis of the information science literature, and consideration of philosophical perspectives, particularly those of Kuhn and Peirce. Results: It is argued that information science may be understood as a field of study, with human recorded information as its concern, focusing on the components of the information chain, studied through the perspective of domain analysis, in specific or general contexts. A particular aspect of interest is those aspects of information organization, and of human information-related behaviour, which are invariant to changes in technology. Information science can also be seen as a science of evaluation of information, understood as semantic content with respect to qualitative growth of knowledge and change in knowledge structures in domains. Conclusions: This study contributes to the understanding of the unique "academic territory" of information science, a discipline with an identity distinct from adjoining subjects. (Contains 1 figure.)