Torah, (תורה) is a Hebrew word meaning “teaching”, “instruction”, or especially “law”. It primarily refers to the first section of the Tanakh–the first five books of the Hebrew Bible, or the Five Books of Moses, but can also be used in the general sense to also include both the Written and Oral Law.
The Five Books of the Hebrew Bible are:
Genesis (Bereishit בראשית),
Exodus (Shemot שמות),
Leviticus (Vayikra ויקרא), Numbers (Bemidbar במדבר) and
Deuteronomy (Devarim דברים)
Collectively they are also known as the Pentateuch (Greek for “five containers”, where containers presumably refers to the scroll cases in which books were being kept), Hamisha Humshei Torah (חמשה חומשי תורה) (Hebrew for “the five parts of the Torah”, or just Humash חומש “fifth” for short) or Chumash.
A Torah is a specially written scroll of the five books, a Sefer Torah. Jews also use the word Torah, in a wider sense, to refer to the entire spectrum of authoritative Jewish religious teachings throughout history. In this sense it might include the entire Tanakh, the Mishnah, the Talmud and the midrashic literature.