Airbag is a passive automotive safety device designed to protect occupants during a collision by reducing injury risks. It works in conjunction with seat belts to form an integrated safety system. When deceleration exceeds a preset threshold (typically 12–15g), sensors send signals to the control unit. After confirming the collision, the unit activates the inflation module, which ignites chemicals (e.g., ammonium nitrate) to produce nitrogen gas. The airbag deploys instantly, then begins deflating before contact with occupants to absorb impact without causing secondary harm.