is a specific kind of: device.

is a broader term that covers: brasier, brazier | convector | defroster, deicer | demister | gas heater | heating pad, hot pad | kerosene heater, kerosine heater, oil heater, oilstove | radiator | solar heater | space heater | stove | hot-water heater, hot-water tank, water heater ... show more.

derivation: heat, heat up | warm | heat.