This chapter highlights the important concepts and aspects of compressible multiphase flows. Compressible multiphase flows are found in several applications related to combustion, explosion, or high-speed systems. The chapter discusses compressible multicomponent and multiphase continua and explains formation of particles from shocked surfaces. It describes dilute and dense particle-laden flows, Reynolds and Mach number defects, particle shock interaction, and dispersed and carrier phase motion. The chapter details multicomponent, multiphase mixtures, which cover a wide spectrum of flow conditions and applications. For multiphase fluids, such as rain drops in air, a spatial averaging approach is used to distinguish between the phases. Compressible multiphase and multicomponent flows can be modeled using an Eulerian approach. In the conservation equations, that is, the Euler equations, the viscous terms are neglected in comparison to the pressure terms. The chapter outlines the carrier phase equations in Eulerian form and the equations for particle motion in Lagrangian form.