When you ask about the “Hebrew holy book,” I assume that you are asking about the scriptures that are held by Jews to be sacred. If that is the case, different people use different names for this scripture. Non-Jews often refer to the Jewish holy book as the Old Testament. The scriptures are also sometimes called the Hebrew Bible, the Torah, or the Written Torah. However, the most proper name for these scriptures is the Tanakh.
While many Americans use the term “Old Testament,” Jews do not use the term because they do not recognize the Christian New Testament as part of scripture. Since there is no new testament in their minds, there is no reason to call their scripture the Old Testament. Many people also use the term “Torah” to refer to Jewish scripture. However, that term most properly refers only to the first five books of the Old Testament, also called the Pentateuch. The proper term for the Jewish scripture as a whole is Tanakh. This term is an acronym for the three sections of the scripture. The first is the Torah, or law. The second is Nevi’im or the prophets. Finally, there is the Kethuvim, or the writings. The beginnings of these three words are made into the acronym Tanakh. This is the term that should be used to refer to the holy book of the Jews.
The Holy Scriptures known by the Jews has three main divisions. The first is also known as the Law of Moses, the Torah. That Hebrew word means "instruction" and the entire volume actually includes the first five books of the Old Testament part of the Christian Bible: Genesis, Exodus, Leviticus, Numbers, and Deuteronomy. The book collection is also called by the name Pentateuch that refers literally to five "tools" or scroll cases.
The other two divisions of the Holy Scriptures for the Hebrews are the Prophets' books' collection and the Writings.