This introduction presents an overview of the key concepts covered in the subsequent chapters of this book. The book suggests that China is currently in the midst of creating a moderately prosperous society in an all-round way. Social and economic development in China is highly uneven, however. The terms moderate prosperity and a moderately prosperous society have been used for quite a long time in China and are now fairly well understood by the Chinese public at large. With the passage of time, the concepts embodied in moderate prosperity evolved. The term came to mean that people in general had adequate food and clothing and lived fairly peaceful lives. Deng Xiaoping's formulation of moderate prosperity and a moderately prosperous society was linked to the adjustments in the country's economic development strategy after the start of reform and opening up. China has made relatively smooth progress in both economic and social terms in the early part of the 21st century.