Question

why are insulators often called as dielectric?​

Answer 1

Answer:

The latter is expressed by a number called the relative permittivity (also known in older texts as dielectric constant). The term insulator is generally used to indicate electrical obstruction while the term dielectric is used to indicate the energy storing capacity of the material (by means of polarization).

Answer 2

Answer:

Dielectrics are materials that don't allow current to flow. dielectric is often used highlight the property of insulator