Interactive video can be a very complex learning system, or it can be a simple tool for teachers to use to enhance their instruction. The term has been used broadly in the literature and includes three major aspects: (1) interactive video as storage; (2) interactive video as hardware; and (3) interactive video as learning concept. This digest describes each of these concepts in detail. The first section discusses the information storage and retrieval capacities of both Constant Angular Velocity (CAV) and Constant Linear Velocity (CLV) videodisks. A scheme for classifying interactive video hardware by "levels of intelligence" (based on a three-level scheme developed by the Nebraska Design/Production Group) is outlined in the second section. Emphasizing learner interaction with visuals, the third section focuses on the advantages of interactive video over other computer-based systems for instructional purposes. (10 references) (GL)