A car bomb is an explosive device placed in a car or other vehicle and then detonated. It is commonly used as a weapon of assassination, terrorism, or guerrilla warfare, to kill the occupant(s) of the vehicle, people near the blast site, or to damage buildings or other property. Car bombs act as their own delivery mechanisms and can carry a relatively large amount of explosives without attracting suspicion.
The U.S. military and law enforcement agencies often call a car bomb a "VBIED", an acronym standing for "Vehicle Borne Improvised Explosive Device", or "SVBIED" if it is used in a suicide attack.
The earliest car bombs were intended for assassination. These were often wired to the car's ignition system, to explode when the car was started. Ignition triggering is now rare, as it is easy to detect and hard to install — interfering with the circuitry is time-consuming and car alarms can be triggered by drains on the car's electrical system. Also, the target may start the car remotely (inadvertently or otherwise), or the target may be a passenger a safe distance away when the car starts.