Old Testament is the Christian name for the books of the Jewish scriptures that constitute the first half of the Christian Bible. "Old" in this sense was a means to distinguish Judaism from Christianity at the creation of the New Testament beginning in the 2nd century CE Jewish believers do not consider their scriptures old, as in no longer valid; they remain at the center of Jewish life and practice.
This is a companion discussion topic for the original content at https://www.worldhistory.org/Old_Testament/.