In schools, children develop the human capital that they will need for socioeconomic attainment, participate in ongoing interactions with adults and other children that will shape their future social and emotional development, and are socialized into the prevailing norms and values of their communities, cultures, and the larger society. As such, schools are an important piece of the developmental ecology, one that is also a major focus of policy, practice, and intervention. This chapter, therefore, explores the significance of schools in child development. It begins with a discussion of key themes in developmental research on schooling, including the place of schools in major theories, the developmental effects of schooling, and the links between schooling and inequality. Next, it explains how schools are societal institutions, structurally organized to facilitate tangible cognitive, academic, and vocational skills among children and to grant key academic credentials. This discussion is followed by a description of schools as developmental contexts, interpersonally organized to shape human interaction and socialization and to influence social and emotional development. These two sides of schooling are brought together in the final section of the chapter, which discusses how schools can be viewed more holistically using several specific examples of controversy in educational policy, such as desegregation and high‐stakes testing. Throughout the chapter, we discuss future directions of research and the translation between research and practice.