The article discusses how children develop concepts and word meanings. The author argues that understanding how concepts are learned is crucial to understanding how they are represented. By studying different types of categories, like natural kinds and nominal kinds, the author shows that children shift from focusing on many features to a few defining ones as they grow. This suggests that even young children have a deeper understanding of categories than previously thought. The research provides new insights into how concepts develop in children and how they are represented in the mind.