What is engine immoboliser in some modern cars?

Question

What is engine immoboliser in some modern cars?

Answer 1

Vehicle Theft Security System helps deter vandalism and break-ins by monitoring doors, ignition and trunk key cylinders.

The Sentry Key or Transponder Key is needed for the Engine Immobilizer that makes it nearly impossible to successfully start without the encoded key, while new lock cylinders contain an extra tumbler to help discourage theft and illegal entry.

If you are able to by-pass this system and start the vehicle without the key the vehicle will shut down within 1/4 mile or on some vehicles it will send out a signal to the monitoring company........

Answer 2

Lets make it simple,its a security measure,prevents theft of a car,when forcefully started with a duplicate key or by some other  means that don't involve using the original key.In an event of a thief breaking into ur car and trying to start it the gear won't get engaged or the ignition will be prevented in the engine.And an alarm will go off alerting the required owner and scaring the thief.