What is the function of Idle Start\/Stop button in Dzire VXI 2020 ?

The idle start-stop function makes the more efficient. It automatically turns off the engine when engine power is not required e.g. when stuck in heavy traffic or a long wait at traffic signals. it automatically starts the engine when we press the accelerator.

Much comphertable in drive and sit I have vxi2018 mileage not good only 17km/ltr build quality is low