Relative permittivity
![Temperature dependence of the relative static permittivity of water](/Images/godic/202502/06/Water_relative_static_permittivity.svg5417.png")
The relative permittivity of a material is its (absolute) permittivity expressed as a ratio relative to the permittivity of vacuum.
Permittivity is a material property that affects the Coulomb force between two point charges in the material. Relative permittivity is the factor by which the electric field between the charges is decreased relative to vacuum.