Critical engineering applications such as jet engines, rocket engines, gas pipelines, wind tunnels, supersonic flight, etc., rely on the flow of fluids at high speeds. At such speeds, the compressibility of the fluid becomes important and must be taken into consideration while designing such applications. In this learning track, we will explore the fundamentals of compressible flows. We will begin by introducing the Basics of Compressible Flows. Then, we will talk about Shock - Expansion Theory and its applications. We will then discuss Internal Compressible Flows which play a vital role in the design of engineering applications. Alternate video link.