Are you trying to be fancy or does yur writing just come off as someone trying to be fancy?
There are certain features of our bodies that are unique to each person. Fingerprints are one, but eye iris pattern is another. The idea is to use one of these features to uniquely identify each eligible voter so that one person cannot pretend to be another. There are now portable devices with computers inside that can take a database of all PNG people's biometric features and compare that against the person whose features are being recorded by the machine. In that way, there's no cheating.
WHAT? No cheating? Of course there's still plenty room for cheating, because after all, it is human beings running all this equipment. The equipment can get accidentally 'broke' in return for a bribe. And that's only a start on how a biometrics-based system can be corrupted.
Of course, you could have leant all this yourself many many days ago if you had bothered to Google biometrics and other key words You could have found the information yourself on the internet. But of course you were too lazy to do that!