Ancestry analysis compares your DNA with that of thousands of people from 93 reference populations around the world. We use SNPs from your autosomes, the 22 pairs of non-sex chromosomes, because each population has characteristic combinations of variants.
The result is the percentage of your DNA that resembles that of each present-day population. If part of your DNA resembles a population's DNA, this suggests that you probably share ancestors with that population; it does not indicate your country of birth or your ancestors' citizenship.
It helps you learn more about your origins, understand how populations have mixed throughout history and see how we are all connected to people from many regions of the world.