This chapter defines the central terms of the book: What is reform, what are the markers of reform, what characterizes processes of reform, what is Salafi-oriented reform and how is Salafi-oriented reform different from Sufi-oriented reform? The chapter presents doctrinal distinction, symbolic distantiation, social separation and spatial segregation as the major features of Salafi-oriented reform. It introduces major intellectual trends of Salafi-oriented reform, it also introduces the major intellectual exponents of Salafi-oriented reform in Africa and stresses the importance of generational change. The chapter points out that movements of reform are not monolithic organizations but characterized by the existence of traditions of dispute on many different levels. The chapter presents the major trends within Salafi-oriented reform that are informed by different approaches to political strategy, education, militancy and piety. The chapter finally discusses different ways of constructing Muslim societies and concludes that such epistemic constructions usually rely on essentialisations that are often misleading when applied to larger social and historical contexts.