admixture
Ancestry that originates from more than one ethnic group.

allele result
Also called a marker value, the numeric value assigned to a genetic marker.

autosomal DNA
All your DNA except what's on the X and Y chromosomes.

biogeographical DNA test
An autosomal DNA test (also called an admixture test) that estimates percentages of your DNA associated with various geographic origins.

confidence range (or confidence interval)
Your DNA results report will show the most likely ancestry percentages (for a biogeographic test) or date an MRCA lived (for a Y-DNA test). It'll also provide a confidence range showing other possible results.

ethnic DNA test
A Y-DNA or mtDNA test in which results are compared to databases containing DNA profiles of populations around the world for matches from particular ethnic backgrounds.

haplogroup
An identification of the genetic group your ancient ancestors (10,000 to 60,000 years ago) belonged to; sometimes referred to as your branch of the world's family tree.

haplotype
Collectively, the marker values on your Y-DNA test results.

HVR, or hypervariable region
Sections of mtDNA (such as HV1 and HV2) that geneticists use to determine your haplogroup.

mitochondrial DNA (mtDNA)
Genetic material mothers pass on to their children.

MRCA
Most recent common ancestor. The most recent ancestor (such as grandparent, great-grandparent, great-great grandparent, etc.) two individuals both descend from.

mutation
Any change in a person's DNA. Geneticists can use mutations in two people with closely matching DNA marker values to estimate how long ago an MRCA lived.

Recombination
The process by which chromosomes cross and switch genetic material at conception.

SNP
Single nucleotide polymorphism. Harmless mutations in autosomal DNA that can indicate your biogeographic ancestry, or where in the world your ancient ancestors came from. Also called admixture markers.

STR
Short tandem repeat. A type of DNA marker scientists can use to determine relationships between individuals.

Y-DNA
Genetic material fathers pass to their sons.