H. Borko wrote, a long time ago (1968), in his article «Information Science: What is it?» a definition about what Information Science is:
Information science is that discipline that investigates the properties and behavior of information, the forces governing the flow of information, and the means of processing information for optimum accessibility and usability. It is concerned with that body of knowledge relating to the origination, collection, organization, storage, retrieval, interpretation, transmission, transformation, and utilization of information. This includes the investigation of information representations in both natural and artificial systems, the use of codes for efficient message transmission, and the study of information processing devices and techniques such as computers and their programming systems. It is an interdisciplinary science derived from and related to such fields as mathematics, logic, linguistics, psychology, computer technology, operations research, the graphic arts, communications, library science, management, and other similar fields. It has both a pure science component, which inquires into the subject without regard to its application, and an applied science component, which develops services and products.» (Borko, 1968)
Furthermore, he talks about some important categories where a Information Science Researcher is able to work. You can see all of them in this (pretty cool) infography that you can share/copy as you want, just using the same license.
Just do not forget, Information Science is an interdisciplinary science, which uses knowledge of several fields to grow and improve.