We have tried to give you an up-to-date but concise idea of how ocean models work. It is our hope that some of you will be motivated by this chapter to pursue Ocean Modeling as a career. Given the grave environmental challenges such as global warming, protein shortages, and environmental pollution facing mankind in the coming century, and because oceans play such a very important role in governing the degree of global warming, fisheries yield, and degree of pollution along our beaches, your study of the oceans through a variety of means (remote sensing, ship surveys, etc.) including numerical modeling can not but lead to a better understanding of how the oceans work. The hope is that as a result, we will leave behind as our legacy to our children, a world that is both livable as well as enjoyable in all its majesty.