A basic wire is made up of conductors and insulators. A conductor is a material, usually metal, that is capable of easily carrying electricity. Conductors are used in wires to carry the power or signal. Insulators are materials which have high resistance to electricity. Insulators are used to coat the conductors and prevent the conductors from shorting against other conductive materials. Typically, protective jackets are used to give the wire resistance against cuts and abrasion. Sometimes shields are used as well to prevent against electromagnetic interference. Electromagnetic interference (EMI) is created when current flows through a wire. In some situations EMI can corrupt the data on signal wires if a shield is not used.