Compressible flow refers to the behavior of fluids, typically gases, when their density changes significantly due to pressure or temperature variations. This phenomenon is crucial in applications like aerodynamics and gas dynamics, where high speeds can lead to substantial changes in fluid properties. In compressible flow, the equations governing fluid motion, such as the Navier-Stokes equations, must account for these density changes. Understanding compressible flow is essential for designing efficient jet engines, rocket propulsion systems, and other technologies where gases are subjected to high speeds and varying conditions.