Haplogroup B (MTDNA) is a type of genetic material, or "DNA" that is passed from our mothers to us. It is a part of a larger group of genetic material called Mitochondrial DNA, or mtDNA. This type of DNA is found in the mitochondria, which are parts of the cells in our bodies. All humans have mtDNA, but some of us may have different types of mtDNA, like haplogroup B. Our mtDNA tells us about our mother's line of ancestry, which can help us trace our family history. Haplogroup B is one type of mtDNA, and it is most commonly found in Asian and Native American populations.