The canonization of the Old Testament is the process by which the books of the Hebrew Bible were decided upon, accepted, and included in the canon. The process was begun in the second century BCE and finalized by the third century CE. During this period, Jewish rabbis debated which books should be included in the canon and which should be excluded. These decisions were based on criteria such as authorship, authenticity, accuracy, and consistency with already established teachings and Judaism as a whole. The canonization of the Old Testament was a significant event in Jewish history, as it established the basis for Orthodox Judaism and provided a source of spiritual guidance for Jews around the world.