Generative Classifier A Generative Classifier builds a good model of a class, and use that to assign how “class-y” is that image. For instance, to categorize cats vs. dogs, we build a cat model and dog model. To classify, then, we see if a particular image is more “cat-y” or “dog-y”. Discriminative Classifier A Discriminative Classifier observes the differences between two classes, instead of trying to model each one.