The use of the terms "genealogy" and "family history" are often used synonymously, but some offer a slight difference in definition. The Society of Genealogists describe genealogy as an "Establishment of a Pedigree by extracting evidence, from valid sources, of how one generation is connected to the next" and family history as "A biographical study of a genealogically proven family and of the community and country in which they lived".
I suppose that would make me more of a "Family Historian". We stand here today, on the shoulders of our ancestors. They struggled, succeeded, failed, loved and lost to give me and those I love a place to start. They handed down numerous traits and tools for our journey. I simply want to know more about them.
Your DNA contains information that has been passed down relatively unchanged from your early ancestors. Three DNA types are of particular interest:
Haplogroups pertain to a single line of descent, usually dating back thousands of years. As such, membership of a haplogroup, by any individual, relies on a relatively small proportion of the genetic material possessed by that individual.
Each haplogroup originates from, and remains part of, a preceding single haplogroup (or paragroup). As such, any related group of haplogroups may be precisely modelled as a nested hierarchy, in which each set (haplogroup) is also a subset of a single broader set (as opposed, that is, to biparental models, such as human family trees).
Haplogroups are normally identified by an initial letters of the alphabet, and refinements consist of additional number and letter combinations, such as (for example) A → A1 → A1a.
In human genetics, the haplogroups most commonly studied are Y-chromosome (Y-DNA) haplogroups and mitochondrial DNA (mtDNA) haplogroups, both of which can be used to define genetic populations. Y-DNA is passed solely along the patrilineal line, from father to son, while mtDNA is passed down the matrilineal line, from mother to offspring of both sexes. Neither recombines, and thus Y-DNA and mtDNA change only by chance mutation at each generation with no intermixture between parents' genetic material.