Here's why:

* Resistance: Resistance is the opposition to the flow of electrical current. A material with high resistance will impede the flow of electricity, while a material with low resistance will allow electricity to flow easily.

* Ohms: The unit of measurement for resistance is the ohm (Ω).

* Superconductors: Superconductors are materials that have zero electrical resistance below a certain critical temperature. This means that electricity can flow through them with no loss of energy.

Important Note: While superconductors have zero resistance, they are not perfect conductors. They still have some other properties, like inductance, which can affect how they behave in circuits.