Definitions
Conductor, Semiconductor, and Insulator
Conductor
Definition: An object that allows electron to flow freely.
Conductors have the least resistance compared to semiconductors and insulators.
You need an Insulator if the circuit needs as much electricity to flow freely as possible.
Semiconductor
Definition: An object that has enough resistance to slow down a current and/or stop a current from losing energy to heat.
Semiconductors have more resistance than Conductors, but less resistance than Insulators.
You need a Semiconductor if you need a circuit to run quickly but also not lose energy to heat.
Insulator
Definition: An object that doesn't allow electrons to flow freely.
Insulators have the most resistance compared to semiconductors and conductors.
You need an Insulator if you need to stop an electric current or touch exposed wires.