What are processes? How should we individuate them? The first part of this chapter sets aside metaphysics to distil a characterization of processes from a consideration of their treatment in science: processes involve parts acting together (at each stage) to bring about the next stage—they are commonly characterized by a rich range of criteria including the nature and arrangement of parts at each stage, how the process exhibits change and self-maintains across stages, and perhaps the role of the process within its larger context. The chapter identifies the tension between this rich view of processes and parsimonious accounts of individuals common in metaphysics (e.g., an individual may be wholly characterized by a list of admissible properties, individuals cannot have other individuals as parts). (Processes can have processes as parts.) The author suggests these tensions may underlie many of the problems of individuation that are the topic of this volume.