In
electromagnetism,
absolute permittivity is the measure of resistance that is encountered when forming an electric field in a medium. In other words, permittivity is a measure of how an
electric field affects, and is affected by, a
dielectric medium. The permittivity of a medium describes how much electric field (more correctly, flux) is 'generated' per unit charge in that medium. More
electric flux exists in a medium with a low permittivity (per unit charge) because of polarization effects. Permittivity is directly related to
electric susceptibility, which is a measure of how easily a dielectric
polarizes in response to an
electric field. Thus, permittivity relates to a material's ability to
resist an electric field (while, unfortunately, the word stem "permit" suggests the inverse quantity).