Computational Fluid Dynamics (CFD) is the study of fluid dynamics problems using a computer. Fluid dynamics studies fluids (that is, liquids and gases) in motion. A computer is used because there is no closed-form (or analytical) solution to its governing equations. The governing equations for a viscous, heat conducting fluid are called the Navier-Stokes equations. For inviscid flows, the governing equations are known as the Euler equations. The foundational laws of fluid dynamics are the conservation laws: the conservation of mass, the conservation of momentum, and conservation of energy. One method for solving these laws is to discretize the region of interest into cells to form a grid. Then a computer algorithm can be applied to the cells of the grid to numerically approximate the governing equations. There are several different Types of Grids including structured grids, unstructured grids, and hybrid grids.