The features of a concept or principle an individual chooses to highlight in an explanation or description may be related to the medium of communication used. Different aspects of understanding can be revealed through words and through drawings. This two-part exploratory study examined the differences between explanations of physical and chemical equilibria generated by means of words or pictures. Participants included both instructors and students, who were randomly assigned to provide either written explanations or drawings of physical or chemical equilibrium at the macroscopic and particulate levels. For both studies, analyses revealed that significantly different features appeared in the written and pictorial explanations of equilibrium. The written responses focused more on processes such as the dynamic nature of equilibrium, whereas pictorial representations highlighted structural aspects of equilibrium, such as the spatial arrangement of molecules. Regardless of the level of chemistry knowledge, people conveyed the same type of information via the use of different representations and visual tools.