This tag is for questions relating to a non-conducting material called dielectric (or dielectric material). Dielectrics are very much important to explain various phenomena in various fields of physics like solid-state physics, optics, electronics, cell biophysics, etc.

Dielectrics are insulating materials that exhibit the property of electrical polarization, thereby they modify the dielectric function of the vacuum. All the charges in a dielectric are bound and thus they cannot support an electric current. In spite of this, the electric field is changed greatly by the presence of a dielectric material.

References:

https://en.wikipedia.org/wiki/Dielectric

https://web.archive.org/web/20190429182422/http://www.pas.rochester.edu/~cline/P114/chapter6.pdf

http://web.mit.edu/8.02t/www/802TEAL3D/visualizations/coursenotes/modules/guide05.pdf