What is the tree of life?

The Tree of Life (Heb. עץ החיים Etz haChayim), in the Book of Genesis, is a tree in the Garden of Eden whose fruit gives everlasting life, i.e. immortality. After eating from the Tree of Knowledge of Good and Evil, the biblical account states, that Adam and Eve are exiled from the Garden of Eden to prevent them from eating of the Tree of Life. The passage actually reads that God set an angel to guard the entrance to the Garden, so that mankind would not eat of the tree and "Be Like Us".