DNA fingerprinting involves identifying differences in some specific regions in DNA sequence, called as

DNA fingerprinting is a technique used to differentiate individuals by examining the pattern of DNA sequences that vary among people.

The variations that are most useful for this purpose are found in regions of the genome that contain repeated sequences. These repeated segments, known as repetitive DNA, occur in many copies throughout the genome, and the number of copies (the length of the repeat region) can differ greatly from one individual to another.

Because the length of repetitive DNA regions is highly polymorphic, they serve as markers that are easy to detect with simple laboratory methods such as polymerase chain reaction (PCR) and gel electrophoresis. When the DNA from two samples is compared, the pattern of bands produced by these repetitive regions will match only if the samples come from the same individual.

Other types of DNA, such as single nucleotides or satellite DNA, are either not sufficiently variable or are not the primary targets used in standard DNA fingerprinting protocols. Therefore, the specific regions that DNA fingerprinting focuses on are the repetitive DNA segments of the genome.