 The logical study of information focuses on some of the most fundamental qualitative aspects of information. Different stances on information naturally highlight some of these aspects more than others. Thus, the information-as-range stance most naturally highlights agency and the dynamics of information in settings with multiple agents that can interact with each other. The aboutness of information (information is always about something) is a central theme in the information-as-correlation stance. The topic of encoding information and its processing (as in the case of formal inference) is at the core of the information-as-code stance. None of these qualitative aspects of information is exclusive to just one of the stances, even if some stress certain topics more than others. Some themes such as the structure of information and its relation with information content are equally pertinent regardless of the stance. The ways in which information is studied in this entry differs from other important formal frameworks that study information quantitatively. For example, Shannon’s statistical theory of information is concerned with things such as optimizing the amount of data that can be transmitted via a noisy channel, and the Kolmogorov’s complexity theory quantifies the informational complexity of a string as the length of the shortest program that outputs it when executed by a fixed universal Turing machine. 