It is suggested that we must distinguish 2 types of object categorization in infancy. One is perceptual categorization, which is an automatic part of perceptual processing that computes the perceptual similarity of one object to another. It creates perceptual schemas of what objects look like. The other is conceptual categorization, which is based on what objects do. It consists of the redescription of perceptual information into conceptual form, particularly the paths that objects take and the interactions among them. This process creates the notion of kinds, such as animals, plants, vehi- cles, and furniture. The similarity in this kind of categorization is of roles in events, not the physical appearance of the objects. Several differences between the 2 types of categories are discussed, of which the most important is the different functions they serve. Perceptual categories are used for object identification; conceptual categories control inductive inference. Experimental results are described showing that because early conceptual categories tend to be global in scope, the inductive generalizations based on them are global in scope as well.