When you are in hilll you have to move your leg from brake to accelerator to push car forward in some case of traffic or starting car. While you do that car may roll back and touch car behind you. In manual transmission people will hold car with handbrake this function is taken care by hill assist.It will keep car at same place while you shift from brake to accelerator
You may have the projector headlamps installed in the VXi variant of Maruti Dzire, however, for the confirmation and availability of the headlamps, please connect with the nearest authorized service center. Follow the link and select your desired city for service centers.