Eve was the first woman, wife of Adam, and the mother of Cain, Abel and Seth, and other sons and daughters. Eve, was created by God in the Garden of Eden from the rib of Adam, who interpreted this as her being "bone of my bones and flesh of my flesh."
And because of this, a man leaves his parents and is "joined to his wife and they shall become one flesh."
Eve was persuaded by a serpent to eat fruit from a forbidden tree in the Garden of Eden. Adam later ate some of the fruit, too. Both were then expelled from the Garden of Eden.
The story of Eve is found in Genesis, chapters 2 and 3.