The term Jew, or Jewish, can refer to either a nationality or a religion.
In biblical times these were one in the same. Nowadays a person can be one without the other. That is, they can be Jewish by birth but not belief, or they could be Jewish in faith but not biologically.
A person can be Jewish by birth, technically a child of a Jewish mother, or become Jewish, in a religious sense, through conversion.
From a human standpoint, Abraham is the founder of the Jewish nation..
Traditionally, the Jewish language is Hebrew, so Jews are sometimes called Hebrews.
