A dielectric is an electrical nonconductor that can be polarized by an applied electric field. When a dielectric is positioned in an electric field, electric charges do not stream through the material like in an electrical conductor, but only slightly shift from their average equilibrium positions causing dielectric polarization.
Positive changes are displaced in the direction of the field, and negative changes shift in the opposite direction. The capacitance of a capacitor infused with a dielectric is more significant than it would be in a vacuum. If the voltage is administered to a dielectric, the atoms within the dielectric arrange themselves in a way that they oppose the flow of electric current.
