Toward the end of Chapter 1 (Section 1.8) it is postulated that many flowfields of interest to the low-speed fluid dynamicist lie in the range of high Reynolds number. Consequently, for attached flowfields, the fluid is divided into two regions: (a) the thin inner boundary layer and (b) the mainly inviscid irrotational outer flow. Chapters 2–13 are entirely devoted to the solution of the inviscid outer flow problem, which indeed is capable of estimating the resulting pressure distribution and lift due to the shape of the given solid boundaries. The laminar boundary layer model was presented in Chapter 14 as an example for modeling the inner part of the complete flowfield. The methodology for obtaining information such as the displacement thickness, the skin friction on the solid surface and resulting drag force (due to surface friction), and the matching process with the outer flow was demonstrated. However, in real high Reynolds number flows over wings the flow is mostly turbulent and the engineering approach to extend the methodology of Chapter 14 to include turbulent or even separated viscous layer models will be discussed briefly in this chapter. The objective of this chapter is to provide a brief survey of some frequently occurring low-speed (wing-related) flowfields and to help the student to place in perspective the relative role of the potential flow methods (presented in this book) and of the viscous effects in order to comprehend the complete real flowfield environment.