What is an electrical insulator?

Insulator can be made from many types of materials such as glass ,porclen, rubber, or plastics.
The insulator stops the electrical charge from going to ground causing the circuit to short out and spark
if you look at a electrical pole you will see insulators that stops the electric from going to earth or commonly called ground if the electrical wires touch ground they flash and short out on the ground

Glass is one of the best electrical insulators and that is why it is used for that purpose in the form of ceramic (hardened glass) insulators on high line poles.

Hello Bagger479,

An electrical insulator is any substance which inhibits the flow of electrons.

Substances like glass, rubber, some vinyl plastics, and ceramics are exellent insulators because they have a very stable atomic structure and do not allow the electrons to be passed from atom to atom.

Good conductors like silver and gold have holes in their outer electron orbits that allow the electrons to flow from atom to atom reletively uninhibited.

Hope this helps.