ASV notes on Genesis 11:26-30
Abraham was at first given the name Abram; God later changed his name to Abraham. Abraham had two brothers, Nahor and Haran, Haran was the first born, and he died in Ur of the Chaldeans, the home town of the Terah family. Excavations has shown that at the time of Abraham (Abram) they lived and existed as we do today in houses with bathrooms, even rooms for guests. They went to schools as children do today and they studied as young people do today. The people of Ur were well educated and smart people.
Abraham married Sarai whose name God later changed to Sarah. Nahor Abraham’s brother married Milcah a daughter of Haran. Haran had two daughters, Milcah and Iscah. Nothing is said about Sarah’s mother or Abraham’s mother, but later we learn that Sarah was Abraham’s half-sister.