What is understanding? What does it mean to understand a phenomenon or aspects of it? In this chapter, I develop an answer to these questions grounded in the notion of “fit”. Understanding phenomena, I argue, is crucially a matter of bringing the corresponding informational units to fit into our existing world-picture, by skillfully deploying a representational system that we reasonably endorse, that is intelligible to us, and that is sufficiently tethered to the facts. The account of understanding that I develop and defend has the following three merits: (i) it is phenomenologically adequate, i.e., it has the resources to explain why we feel in a certain way, when our efforts to understand reality succeed or fail; (ii) it enables us to draw a clear line between understanding and the subjective feeling or sense of understanding; (iii) it gives us a clear picture of what it means for understanding to improve.