DNA fingerprinting is also called DNA typing. Alec Jeffreys is credited with developing this technique in 1984. Jeffreys found that within each gene, certain sequences of DNA are not required to do anything. In a sense, they simply exist within the gene. Normally, these sequences are named minisatellites. The minisatellites are unique to individuals. The only individuals which have been found to share satellites are those born from the same zygote (identical multiples in birth, cannot be fraternal). DNA fingerprinting has been used in paternity and crimes.
In order to complete a DNA fingerprint, cells mast be collected. Typical collection cells are hair, skin, and blood. After being purified, cut, electrified, split, and exposed to radioactive pieces of other DNA, the patterns of minisatellites emerge.