1) Concepts are represented in different ways including prototypes, exemplars, and schemas. Prototypes represent concepts as central tendencies while exemplars represent individual category members. 2) The basic level of categorization, such as chair or dog, provides the optimal balance between predictive power and accuracy. It is also the earliest learned and most natural level of naming. 3) Exemplar models better explain categorization data by accounting for variability and typicality effects compared to prototype models which lose information about individual exemplars.