This chapter involves a particular type of representation that has a long history in computational accounts and that is increasingly viewed as a promising way to make sense of representation in the brain. It presents a general explanation of the notion of representation and discusses some of its central aspects. The chapter provides a few illustrations of how the notion of representation has appeared in computational accounts of the mind. It addresses some common criticism of this way of thinking of representation in the brain. The authors use external models and maps to acquire information, make predictions, and navigate through the world, so too, investigators claim that the computational brain uses its own neural models and maps to perform various cognitive tasks. Models thereby often replace not just entities and their parts with proxies, but also relations, properties, values, and a host of other dimensions of the target domain.