Final answer:
An insulator is a material that does not allow electrical current to pass through it, as opposed to conductors which do. Insulators have tightly bound electrons and can be vastly more resistant to charge flow than conductors. Options such as semiconductor and superconductor have different levels of electrical conductivity.
Step-by-step explanation:
Material such as glass, rubber or paper around a conductor that does not allow current to pass through it is known as a(n) insulator. These materials do not permit the charge carriers, particularly electrons, to move freely because the electrons are tightly bound to the atoms within the material's structure. As a result, insulators can be up to 1023 times more resistant to the flow of charge than conductors.
Conductive materials, on the other hand, allow charge to move through them with relative ease. The opposite of a conductor is a semiconductor, which conducts electricity better than an insulator but not as effectively as a conductor; and a superconductor, which allows current to flow without any resistance under certain conditions.