The Word "Torah" (best translated as "Instruction" in English) has three meanings in Judaism today:
The most specific meaning includes only the five books revealed to Moses at Sinai. This is known as the "Pentateuch" in Western culture, a word derived from the Greek, meaning Five ("Penta") Tools ("Teuko"). These five books are also known as the "Chumash" in Hebrew.
Then, we have a broader meaning, where "Torah" includes the books of the Chumash as well as the Prophets ("Neviim" in Hebrew) and the Writings ("Ketuvim" in Hebrew). These three components together are called "Torah", as well as TaNaKh (a acronym for "Torah-Neviim-Ketuvim"). Essentially, the books of the Chumach plus the Neviim plus the Ketuviim were the sacred written scripture of Judaism since Moses; hence they are also called the "Written Torah" ("Torah Shebiktav" in Hebrew).
In addition to the Written Torah, most denominations today uphold that Judaism also received a Oral Revelation at Sinai. The historian Josephus (writing around 85 CE) records that the Pharisees were the main party which practiced and advocated the Oral Law. By contrast, the Zadukkim (Saducees) did not believe in the revelation of a Oral Torah and hence were in constant tension with the Pharisees. It is not clear whether the third party in Jewish denominations at that time (referred to by Josephus and other historians as the "Essenes") believed in the Oral Law revelation or not. In Judaism today, most denominations descend from Pharisaic Judaism (known today as Rabbinical Judaism); those are the Orthodox, Conservative, Reform, Liberal, Reconstructionist, and Progressive denominations. All of them recognize the Oral Law (with varying degrees absoluteness). By contrast, there are smaller denominations or sub-ethnic groups who either reject or simply have not received the Oral Torah as a revelation. The Karaite Jews do reject the concept of a Oral Torah. Sub-ethnic groups such as the Ethiopian Falasha existed for the last two millenia in Ethiopia without knowing about the Oral Law. At any rate, for those denominations who recognize a Oral Torah ("Torah Shebeal Peh" in Hebrew). Hence, for Rabbinical Judaism today, the word "Torah" has a third meaning, which is that of the "Written Torah" plus the "Oral Torah" combined.
The compents of the Written Torah are as follows:
* Torah: This is the part that was given directly to Moshe Rabbeinu (Moses our Teacher) at Mount Sinai. It is made up of five books.
o Bereishit (Genesis)
o Shemot (Exodus)
o Vayikra (Leviticus)
o Bamidbar (Numbers)
o Devarim (Deuteronomy)
* Neviim (Prophets): Prophets are great and saintly people who communicate with Yhwh. These books are recordings of some of what Yhwh said to His prophets.
o Yehoshua (Joshua)
o Shoftim (Judges)
o Shmuel (Samuel) - two books
o Melachim (Kings) - two books
o Yirmiyahu (Jeremiah)
o Yechezkel (Ezekiel)
o Yeshayahu (Isaiah)
o The following twelve are combined in one book called Trey Asar (The Twelve):
1. Hoshaia (Hosea)
2. Yoel (Joel)
4. Ovadiah (Obadiah)
5. Yonah (Jonah)
6. Mihhah (Micah)
7. Nachum (Nahum)
8. Hhabakkuk (Habakkuk)
9. Tzefaniah (Zephaniah)
10. Hhaggai (Haggai)
11. Zehhariah (Zachariah)
* Ketuvim (Writings): These books were written by prophets with Yhwh's guidance but are not direct prophecies.
o Tehillim (Psalms)
o Mishlei (Proverbs)
o Iyov (Job)
o The following five books are called Megillot:
1. Shir HaShirim (Song of Songs)
3. Eichah (Lamentations)
4. Kohelet (Eclesiastes)
o Ezra & Nechemiah
o Divrei HaYamim (Chronicles) two books
All together there are 24 books in the Written Torah or TaNaKh: five in the Torah (Pentateuch), eight in the Neviim (Prophets), and eleven in the Ketuvim (Writings).
Now, many things are not explained in the Written Torah. The Pharisaic/Rabbinical revelation is that Yhwh gave these additional explanations to Moses on Mount Sinai together with the Written Torah. These explanations are called the Torah Shebeal Peh, the Oral Torah, because they were meant to be passed from teacher to student.
In the years after the destruction of the second Temple (Beit HaMikdash, or Holy House) there was a danger that the Torah Shebeal Peh would be forgotten. Therefore, the Rabbinical Sages, led by Rabbi Yehudah HaNasi (The Prince), assembled a basic outline of the Torah Shebeal Peh into a series of books called the Mishna. The Mishna was completed in the year 188 CE. The Mishna was intended to serve as a memory aid so that it would be easier for students to remember the Torah Shebeal Peh. The Mishna was primarily an outline and did not include the in-depth analysis and explanation behind the laws. These explanations are called Gemara.
About three hundred years after the completion of the Mishna, there was a risk that the Gemara would be forgotten. Once again, the Rabbinical sages, now led by Rav Ashi and Ravina, compiled the Gemara into a written work as a commentary on the Mishna. The Mishna and the Gemara together form what is today called the Talmud.
The Talmud is made up of six sections. Each section is called a Seder (Order) and contains several books called Masechtos (Tracts). The six Sedarim (Orders) are:
* Zeraim (Seeds), this section deals with the laws of agriculture. It also deals with the laws of prayer and blessings. It contains 11 Masechtos.
* Moed (Season), this section deals with the laws of Shabbat and Yom Tov (holidays). It contains 12 Masechtos.
* Nashim (Women), this section deals with the laws of marriage and divorce. It contains 7 Masechtos.
* Nezikin (Damages), this section deals with civil law, such as laws about damages and theft. It also deals with ethics. It contains 10 Masechtos.
* Kedoshim (Holy Things), this section deals with sacrifices. It contains 11 Masechtos.
* Taharat (Purities), this section deals with laws of ritual purity. It contains 12 Masechtos.
And these are all the books that have been revealed to Israel.