They are in almost every human cell and its sequence of nucleotides is different in each one of the them. The DNA fingerprint includes intron because exon are more conserved so they have less variability in their sequence.
The orginal answer is on encyclopedia, I change the wording in order to advoid plagerism. I hope I helped :)
Explanation: Race is a heritage that various and diverse group of people use to identify with each other. Race may include physical characteristics such as the skin color example the black race and other associated traits such as facial features and hair texture
