What is the difference between the resistance of conductor and insulator?

Conductors allow most, if not all, electricity to pass through it. This is due to "wandering electrons" that aren't tightly bound to the nucleus of the conductor itself.

Resistors conduct some, but not all electricity to pass. It somewhat resists it, hence resistors.

Insulators do not allow electricity to pass through it due to the electrons being so tightly bound to the nucleus.