In physics, the electric displacement field is a vector-valued field

<math>\vec D<math>

that appears in Maxwell's equations and that generalizes the electric field. In fact, "D" stands for "displacement".

In most ordinary materials, <math>\vec D<math> may be calculated as

<math>D = \epsilon E<math>

where <math>\epsilon<math> is the permittivity of the material.

The electric displacement field is sometimes known as the "macroscopic electric field," in contrast to the electric field E, which is analagously the "microscopic electric field." The difference is that the macroscopic field "averages out" the jumble of electric fields from charged particles that make up otherwise electrically neutral material.