A sign is the most basic unit of representation. A semantic Network is the process of identifying stimuli in a certain environment and putting them in memory as parts of a category. Prototype is an object so central to the category it contains all of the characteristics that are used to define a category. Arbitrariness of Symbol's Relationship is basically the fact that even though symbols represent organizations or other things, that fact is arbitrary. It only means that because we assigned that meaning to it.