Here's a bit more detail:
* Conductors have many free electrons that can easily move throughout the material. This allows for the flow of electrical current. Examples include metals like copper, silver, and gold.
* Insulators have very few free electrons and resist the flow of electrical current. Examples include rubber, plastic, and glass.
* Semiconductors fall somewhere in between. They can act as conductors or insulators depending on factors like temperature and impurities. Examples include silicon and germanium.
