Generations of Noah

Based upon the theory that all current humans are descendants of Noah, some medieval scholars posited that the peoples of the world could be placed into one of three categories corresponding with each of Noah's sons. These ideas continued to be taken seriously until the 19th century, even though we now know that they have no basis in historical fact.

The huge advances made by 20th century archaeologists, anthropologists, and ethnographers have served to place this theory in to the realm of "quaint old belief." Their use now shows an outdated pre-20th century view of the world, even though terms like "Semitic people" are still in public use.

In linguistics, however, "Semitic languages" is an established term for a well-defined concept. See Semitic.

The medieval concept was as follows:

The continent of Africa was associated with the descendants of Ham.
The term "Semitic people", denoting both Arabs and Jews.
...and presumably everyone else was a descendant of Japheth