What is the difference between dynamic viscosity and kinematic viscosity?

Dynamic viscosity (μ) measures a fluid's internal resistance to flow when an external force is applied, with units of Pa·s or Poise. Kinematic viscosity (ν) is the ratio of dynamic viscosity to fluid density (ν = μ/ρ), with units of m²/s or Stokes. Dynamic viscosity is used when dealing with forces and stresses, while kinematic viscosity is preferred in equations involving gravity-driven flows or when density effects are considered separately.