What does the 'rest' in a car mean?

[SanBrantley]

The 'rest' in a car refers to the residual heat function, which utilizes the engine's residual heat to continue providing warm air inside the cabin for up to half an hour after the engine is turned off, before automatically shutting down. The rest button function is particularly useful during short winter stops when the engine is turned off, as it helps maintain the interior temperature, preventing a rapid drop in temperature. This means there's no need to turn on the air conditioning system to reheat the interior when restarting the vehicle. The working principle of the rest function is: after the car's engine is turned off, it uses the engine's residual heat to supply warm air to the cabin, preventing a rapid temperature drop. The heating duration is typically half an hour, after which it automatically turns off.