What are the differences between "dielectric constant" and "electrical permittivity"?
By searching on the net, I found permittivity = absolute permittivity, which is the measure of capacitance that is encountered when forming an electric field in a particular medium. The lowest permittivity is that of a vacuum: vacuum permittivity = electric constant. In addition, relative permittivity of a dielectric medium is represented by the ratio of its absolute permittivity to the electric constant.
Therefore, I think the "electrical permittivity" in many literatures should be equivalent to absolute permittivity above. But what is "dielectric constant"? Any suggestion?