resistance(The ability to impede (resist) the flow of electric current. With the exception of superconductors, all substances have a greater or lesser degree of resistance. Substances with very low resistance, such as metals, conduct electricity well and are called conductors. Substances with very high resistance, such as glass and rubber, conduct electricity poorly and are called nonconductors or insulators); resistor(A circuit component designed to provide a specific amount of resistance to current flow)