Theory of hydrodynamic concerned with predicting the most stable and unstable configuration for a given system, and transition of the system from laminar flow to turbulent flows as a natural progression marked by the initial instability.Laminar flow is a type of flow in which the fluid particles move in layers. There is no transportation of fluid particle from one layer to another.Turbulent flow is the most common type of flow that occurs in nature.There is transportation of fluid particle from one layer to another. The most stable configuration of a two fluid interface is one in which the lighter of two fluids exists on top of the heavier fluid.