The name given to a region of DNA that varies from person to person is a polymorphism.

Here's why:

* Polymorphism literally means "many forms".

* In genetics, a polymorphism refers to a DNA sequence variation that is common in a population (usually found in at least 1% of the population).

* These variations can be single nucleotide changes (SNPs) or larger deletions, insertions, or rearrangements.

* Polymorphisms are what make each person's DNA unique, even within families. They are used in many applications, including:

* Genetic testing: To identify disease risk factors or ancestry.

* Forensic science: To identify individuals from DNA samples.

* Population genetics: To study human evolution and migration patterns.

Let me know if you have any other questions about DNA!