Rabbinical Judaism, one of the three major monotheistic religions of the world, the tenth largest religion in the whole world.
It originated in the Mesopotamia area, what we now call Syria, Iraq, Israel, Palestine, and Jordan. It originated from the ancient Israelite religion that was organized by King Josiah, the 16th King of Judah, who reigned from 640 BC to 609 BC. Although credit of it's founding often goes to Abraham the Patriarch or Moses.

Their Holy Texts are the Hebrew Bible or Tanakh, what Christians call the Old Testament, it is composed of the Torah, the Five Books of Moses (Genisis, Exodus, Numbers, Leviticus, Deuteronomy), the Nevi'im (Joshua, Judges, Samuel, Kings, Isaiah, Jeremiah, Ezekial, Hosea, Joel, Amos, Obadiah, Jonah, Micah, Nahum, Habakkuk, Zephaniah, Haggai, Zecharia, Malachai), and the Ketuvim (Psalms, Proverbs, Job, Song of Soloman, Ruth, Lamentations, Ecclesiastes, Eshter, Daniel, Ezra, Nehimiah, Chronicles). In the Tanakh the Christian books of 1st and 2nd Samuel, 1st and 2nd Kings, and 1st and 2nd Chronicles are put into one book each respectively.

The Torah is the story of creation, how God (Adoni, Elohim) chose Abraham, Jacob's descendants being sent into slavery in Egypt, Moses delivering them in God's name, and Moses giving them the law.
The Nevi'im is the Prophets of Israel, they are categorized into three groups, the four Former Prophets, the three Major Prophets, and the twelve Minor Prophets.
The Ketuvim consists of the Poetical Books, the Megillot (Scrolls), Prophecy, and History.

The name "Judaism" comes from the Kingdom of Judah, which is said to have descended from one of the sons of Jacob who goes by the same name.

Rabbinic Judaism also uses other texts aside from the Tanakh for their research, the also use the Talmud and the Mishna Torah, which are collections of writings and commentaries of the Rabbis (teachers) and Sages throughout history, but mainly from the time of the Babylonian Exile in 598 BC to 538 BC and the short time after that.
Some notable practices of Judaism are adherence to a strict dietary law, celebration of the High Holy Days that include Passover, The Feast of Unleavened Bread, First Fruits, and Shavout for the spring holidays and Rosh Hashanah, Yom Kippur, and Sukkot for the fall holidays, other practices include strict observance of the Saturday Sabbath, and, for some sects, wearing of a head covering called a Kippah or Yarmulke (yah-muh-kuh).

In summary, Jews are monotheistic, or believing in one God, that the Torah is the Holiest Text, and that the Jews are the Chosen Israelites. Although, many individual Jews can believe varying things, and some are only culturally Jewish and follow none of these laws.