Electricity

Substances which allow electricity to pass through them easily are called conductors. These are made from materials which have low resistances. Metals like copper, aluminium, silver, iron, brass and also salt solutions are good conductors of electricity.

Substances which do not allow electricity to pass through them easily are called insulators. These are made from materials which have a high resistance. Some substances like  air, plastic, cotton, rubber, wood, paper, glass, pure water, etc are insulators.