Race is simply a way to categorize human beings. This categorization can be done by language, by appearance (skin color etc), by genetics, names, or parentage.
From God's point of view, God categorizes human beings into the elect and the non-elect, so there are only two races from God's point of view.
According to the biblical definition of race, it is defined according to ancestral lines not appearance. There is nothing in the bible which says that Jesus was descended from David because he had a certain appearance about him or because he had some of David's DNA. His race was due to his ancestral line on the father's side. The concept of race was strongly linked to the family tree on the father's side. So if God is our Father, we belong to God's race, and if satan is our father, we belong to satan's race. Appearance and physical genetics doesn't come into it at all.
But in our modern day, race is strongly linked to genetics. A few hundred years ago, Darwinian evolution introduced the idea that race is attributed to genetics and features such as skin color, eye appearance, hair color etc.
Many bad things were done by colonial powers fueled by Darwinian thought that the white color had certain advantages over other colors according to the belief that it is all about genetics.
At the same time, whole people groups were labelled according to their appearance, despite the fact that within these people groups exist very different cultures, foods, languages, and religions.
This led to Hitler's views about the different races being superior to others, and he was merely taking the prevalent belief in Europe at the time, that one step further.
So in summary, In bible times, races were defined by culture and religion.
In modern times race is defined by genetics.
In God's view, race is defined by whether or not you are of God's seed or satan's seed. That is, whether or not God is Father or not.