A third cousin is a relative with whom you share a common great-great-grandparent. In simpler terms, if you trace your family tree back to your great-great-grandparents, a third cousin is someone who is descended from one of those ancestors, just like you are, but through a different branch of the family.
To explain further, consider this: your great-great-grandparents had children, and those children are your great-grandparents. Each of those siblings would go on to have families of their own, and those families can interconnect over generations. A third cousin is then found two generations down from that great-great-grandparent, hence the ‘third’ designation.
While third cousins do not share a lot of DNA—typically only about 0.78%—they are still part of the extended family network, which can foster a sense of shared history and identity among relatives. Understanding family relationships can help in exploring genealogical connections and discovering more about one’s heritage.