Final answer:
A conductor is a material that allows electric current to pass through it. These materials have free electrons that can move relatively freely through them.
Step-by-step explanation:
A material that allows electric current to pass through it is called a conductor. These materials, such as metals and salty water, have free electrons that can move relatively freely through them. The moving electrons in a conductor may collide with fixed atoms and lose some energy, but they can still move and allow the flow of electric charge.