Although the location of airbag sensors may vary according to the model of the car, most cars have airbag sensors on the dashboard and along the side of the vehicle. When not in use, airbags are deflated, compressed and tightly packed into their containers.
When the car's control unit senses an accident, it signals the car's inflator system, which triggers a chemical charge that releases the nitrogen gas that inflates the airbag. The inflated airbag quickly bulges from its location to cushion the passengers in the car against injury by absorbing shock. After the collision, the airbag automatically deflates itself.