"Seen" and "Unseen" are terms often used to describe the exposure or familiarity of an object, event, or phenomenon. "Seen" refers to something that has been perceived, experienced, or observed previously. On the other hand, "Unseen" refers to something that has not been previously perceived, experienced, or observed and is therefore unknown or unfamiliar. These terms can be used in various contexts, such as in literature, science, or everyday life.