Materials that allow the charges of an electric current to move freely through them are called conductors.

Here's why:

* Conductors have free electrons that can easily move throughout the material when an electric field is applied. This allows the electric current to flow readily. Examples include metals like copper, silver, and gold.

* Insulators are materials that resist the flow of electric current. Their electrons are tightly bound to their atoms and cannot move freely. Examples include rubber, glass, and plastic.