Question

WHAT EXACTLY IS THE DIFFERNCE BETWEEN INSULATOR AND DIELECTRIC

Answer 1

they are basically the same..
in wikipedia the definition of dielectric is
"A dielectric is an electrical insulator that can be polarized by an applied electric field."

Answer 2

insulator is related to resistance and dielectric is related to polarisability/susceptibility..
most of the insulators are also dielectrics but not the vice versa..

Answer 3

Also check this;

http://www.electrotechnik.net/2010/03/what-is-difference-between-insulator.html

Answer 4

Dielectrics are perfect insulators and insulators dont conduct electricity.

Answer 5

Dielectric - everything is dielectric, even there is a dielectric strength of vacuum.
Conductor - conductors are those dielectric which are conducting electricity at present condition (i.e potential difference, temperature,pressure)
Insulators - insulators are those dielectric whose dielectric strength is not broken at present conditions.