The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water.

Kinematic viscosity:

Kinematic viscosity is defined as the ratio of dynamic viscosity and density of the fluid.

Kinematic viscosity = Dynamic Viscocity/Density of fluid

V = µ/ρ

Dynamic Viscosity (µ):

• Viscosity can be defined as the measure of a fluid's resistance to deformation at a given flow.
• For instance, when a viscous fluid is forced through a tube, it flows more quickly near the tube's axis than near its walls.
• In such a case, experiments show that some stress (such as a pressure difference between the two ends of the tube) is
  needed to sustain the flow through the tube.
• This is because a force is required to overcome the friction between the layers of the fluid which are in relative motion.
• So for a tube with a constant rate of flow, the strength of the compensating force is proportional to the fluid's viscosity.

?∴ It represents the property of the fluid to maintain its momentum.