This chapter introduces the fundamental principles and concepts of school inspections. School inspections will be defined and distinguished from other types of evaluation, such as quality monitoring, internal evaluations and audit. The chapter will also present examples of different inspection practices across Europe and explain how these have evolved over the last decades, while the goals and functions of school inspections to control and support schools have remained relatively stable. Many Inspectorates of Education try to meet both goals when inspecting schools and the last section of the chapter will discuss potential conflicts that may arise from combining both goals. [For the complete volume, "Methods and Modalities of Effective School Inspections. Accountability and Educational Improvement," see ED609327.]