This chapter examines the concept of civil society. During the 1990s, civil society was a relatively obscure concept familiar mostly to scholars of Marxism. It then evolved into a mainstream term freely used by social science analysts in general, and by practitioners in the international assistance field in particular. Several factors contributed to these developments, including the growing interest in the United States and many European countries in promoting democracy abroad at that time. The chapter first defines civil society before discussing traditional vs modern civil society. It then considers the rise of civil society as an entity separate from the broader society and from the state, along with the state-civil society relations in the developing world. Finally, it explores how the concept of civil society became an important part of discussions of democratization.