Answer

Electrical resistivity is a measurement of how well a substance resists the passage of electricity, whereas conductivity is a measure of how easily electricity flows.

The heater’s heating element is composed of an alloy with a high resistance. As a result, when electricity passes through the heating element, it heats up. Due to the heating impact of electricity, it becomes excessively hot and glows red.
However, the resistance of cable, which is generally made of copper or aluminium, is relatively low.