Workers in railroad occupations ensure that passenger and freight trains run on time and travel safely. Some workers drive trains, some coordinate the activities of the trains, and others operate signals and switches in the rail yard.
A good conductor allows the electric current to pass through it freely while an insulator does not allow the electric current to pass through it. Conductors are mostly metals like copper. Insulators are mostly non-metallic solids which have extremely high resistance towards the flow of charge and do not allow the charge to flow through them.