What are wires called that allow electricity to flow through them?

The term you're looking for to describe wires that allow electricity to flow through them is "conductors." Conductors are materials that permit the flow of electrical current due to the presence of free electrons that can move easily within the material. Common examples of conductors include metals like copper and aluminum, which are widely used in electrical wiring.

The other terms mentioned refer to different concepts within the realm of electricity. Circuits refer to a closed loop that allows current to flow, connectors are devices used to connect electrical components, and insulators are materials that hinder the flow of electricity by preventing electrons from moving freely. Understanding the role of conductors is crucial in practical applications involving electrical systems, as they form the backbone of how electricity is distributed and utilized in various devices and infrastructures.