Aero-dynamics, the study of the motion of air and other gases in relation to the movement of objects through them, has spawned a variety of synonyms. A few of the most common include aeromechanics, aerophysics, fluid dynamics, and hypersonics. Each term reflects a different aspect of this complex discipline. Fluid dynamics, for example, is a more general term that includes the study of liquids in addition to gases, while aerophysics focuses specifically on the physical properties of air. Hypersonics, on the other hand, is concerned with the study of high-speed airflow, typically above Mach 5. Regardless of the term used, however, aero-dynamics remains a fascinating and essential field of study in many areas of science and engineering.