Answer: DNA fingerprinting is a technique of identifying a person from the unique pattern of bands formed by his DNA.
Every person (except identical twins) has a different sequence of nucleotides in the non-coding regions of DNA. The DNA is cut by enzymes, the fragments are separated by electrophoresis and a pattern of bands like a bar-code is obtained. This pattern is compared with a sample to identify the person.
It is mainly useful in forensic science to identify criminals from blood, hair or semen found at the scene of a crime, in settling cases of disputed parentage and inheritance, and in identifying dead bodies.