Step-by-step explanation:
Biometrics is a modern term and is used basically to identify any individual.
It is the most technical term used measure people's physical and biological characteristics. It is the measurement of an individual's unique features as some of the body features vary for every individual. It is an important tool for identification.
Biometric verification is done in a way that every person can be identified uniquely based on his distinguish biological features. These includes fingr prints, retina and iris patterns, hand geometry, DNA, voice waves, signatures, etc.
It is used to identify and access control, and is used to identify or distinguish each and every individual who are in a group and are under surveillance.
Government agencies and law enforcement can make use of biometric identification features to identify any crime suspect person by tracking down his or her biometric features. This is useful because every person has different biometric features who are different for every person.
The government can take down the biometric measurements of any known terrorists and can prevent the terrorists access to any heavily populated which is put under surveillance. They can do this by installing some identifying devices in that area which alarms the law enforcement people when such a match biometric features is identified in the devices that is under surveillance.