Question

What does it mean by good conductor and bad conductor?

Answer 1

The term good conductor or bad conductor depends on what context it has been asked. For electricity: good conductors are the one which allows the flow of current without offering much resistance while the bad conductors are the one which offer sufficiently high resistance to seize the flow of electric current.

For thermal conductance: good conductors are the one which conducts heat, e.g iron, copper etc. And bad conductors are the one which does not allow the flow of heat through itself, e.g, wood, plastic, etc.