Definition - What does Dielectric mean?
A dielectric material is a type of insulator which becomes polarized when it comes in contact with an electrical field. It can easily support an electrostatic field even though it is not a conductor of electricity. Such materials are used in many places such as in capacitors and radios, as well as transmission lines for radio frequency. It can be used to store energy too, if it is configured properly. Most of these materials are solid in nature, but some fluids and gasses also exhibit dielectric properties. An example of such a gas is dry air, while examples of solid dielectrics include mica, ceramic, plastics and glass. Distilled water is a dielectric liquid.
Techopedia explains Dielectric
As dielectric materials are not conductors, electric charges do not flow normally through them when they come in contact with an electric field. The charges do not actually flow, but move slightly from their original position. This results in a dielectric polarization. It causes the positive charge in the material to go toward the electrical field and the negative charges to do the opposite. Thus, an electrical field is created in the material itself and it reduces the overall field of the material. If the molecules of the material are bonded weakly, then they even realign themselves based on their symmetry axes. Another major property of dielectric materials is that they do not waste energy in the form of heat while supporting an electrostatic field. This property exhibited by certain materials, allowing the creation of high-grade capacitors.