The purpose of this chapter is to introduce the concepts of air quality management and related aspects such as air quality monitoring and emission source management. A number of related concepts include understanding of what air quality monitoring is, why it is conducted, and understanding of the factors involved in conducting air quality monitoring activities; familiarity of different sampling approaches and techniques for gas- and particulate-phase pollutants; understanding of how pollutant concentrations are calculated and expressed; knowing differences between accuracy, precision, and bias and their importance in air quality data; understanding of the importance of calibration and its application to air quality monitoring; familiarity of federal air quality monitoring requirements and the most important air quality monitoring networks; understanding of the importance of federal reference and equivalent methods; understanding of the importance of quality assurance and quality control programs; familiarity of graphical and simple statistical data summarization techniques for air pollution data; understanding of how air quality indices are determined and the purpose for which they are intended; becoming familiar with emissions assessment methodologies; enabling access and use of emission factors to determine emissions of regulated pollutants from sources; and familiarity of principles underlying air quality models and their use.