When a child learns to call only cars by the name car, has he or she learned the meaning of car, the concept of cars, or both? Could the child have learned one without the other? Imagine an adult who calls some tree an oak when it is really a maple. Does this person not know the correct meaning of oak or is he or she confused about the category of oaks? Or do these questions amount to the same thing? The goal of this chapter is to analyze the psychological representation of word meaning and to determine its relation to concepts. In carrying out this goal, we will also need to consider philosophical views on what word meaning really is.