- Conductors: These are materials that allow electric current to flow easily because they have free electrons. Examples: Copper, silver, aluminum. These are used in wires and electrical components.
- Insulators: These materials do not allow electricity to pass through easily because they have tightly bound electrons. Examples: Rubber, glass, plastic. These are used for insulation in electrical wires.
- Semiconductors: These materials have electrical properties between conductors and insulators. Their conductivity can be controlled by adding impurities (doping). Examples: Silicon, germanium. These are used in making transistors and diodes.
Each of these materials plays a critical role in electrical and electronic circuits.