Fluid motion is ubiquitous in the world around us. There are countless situations in which the understanding and harnessing of fluid motion provide the means for improving our lives. The heating and cooling of our homes and workplaces, the operation of engines for power and transportation and the transport of working fluids through pipelines and channels are a few examples. Our task in this and the next chapter is to develop a set of concepts that will allow a systematic examination of fluids in motion and their related effects. This is a logical progression beyond the fluid statics considerations examined in the previous chapter.