So i have been delving into the realm of electrodynamics for the first time in an independent study that i'm doing but i am having trouble conceptualizing some vital concepts. one of them is D, the electric displacement field. Most texts don't even bother to explain what D is or where it comes from. they mostly introduce it as a continuity condition. i'm confused since i'm not sure if it is an actual real thing or not (like an E field). perhaps i'm taking the wrong approach in trying to understand it. So we have two plates that are oppositely charged and we place a polarizable material in between these two plates. the E field is less inside the material because of the attraction of opposite charges to the plates (which sets up an opposite E field inside). now where is D? the text i'm reading now (electrons in solids by richard bube) says that D is the same in between the material and the plates and inside the material. what does that mean? the charge density is the same everywhere in between the plates? now D has units of C/m^2 or charge per area meaning that it is a charge density or charge flux. since it is called a field, which means "action at a distance" i'm not seeing the action that is taking place at a distance? i'm trying to relate this to the E field. which can be easily understood by setting up the oppositely charged plates like we did before (the field exists in between the plates). so where is D? how can you set up D? my main question is what is D? where does it come from? what contributes to it? i talked to one of the phd students in the lab and he said that it is entirely a material property and its description gets really hairy when you get to nonisotropic materials or large E fields like lightning and he started blabbering (that's what it sounded like to me) about some crazy math i didn't understand. so for you brainiacs outt here...please no talk about tensors. Thanks guys. edit: also i'm trying to think about the analogy between the e-field and the h-field. i remember when i took the basic EM physics class and learned about lorentz force they were always talking about an applied B field (to deflect the charge in motion). is this the same B-field when talking about maxwell's equations? if it is, then there is an H field set up by a dipole and the flux lines are the B so then by analogy you set up an E field with oppositely charged plates (a dipole?) and the flux lines are D?