Dielectics and insulators are considered synonymous terms.
but they r not. "dielectric" is more often used to describe
materials where the dielectric polarization is important,
such as the insulating material between the metallic plates
of a capacitor, while "insulator" is more often used when
the material is being used to prevent a current flow across
Thus all dielectics are insulators but all insulators are
the main difference between dielectric & insulator is the
dielectric used where energy is stored. like capecitor. but
in case of insulator we used it as a wall which do not
provide any path to flow current through it. the dielectric
is also a insulator.
The difference between dielectric and insulator lies in its
field of application. Dielectrics are used to store the
electric charges, while insulators are used to block the
flow of electric charges (they more or less act like a
wall). While all dielectrics are insulators (they don't
allow the flow of electric charges through them) all
insulators aren't dielectric because they can't store
charges unlike dielectrics.
The difference between dielectrics and insulators depends on the field of application.That means, dielectrics are used to store electric charges and even can conduct electricity after its dielectric strength(which is the strength of the dielectric to store charges with maximum value of electric field, This situation,when dielectric conducts electricity breaking down its main property of storing charges, is known as dielectric breakdown ).
Whereas Insulators neither store electric charges nor conduct electricity in any situation.
All insulators are dielectric but all dielectrics are not
insulators.This means only certain insulators can posses
dielectric,where an insulator gets a minimum charge in the
presence of electric field known as dielectric.