Oneiromancy
Oneiromancy (Greek oneiros, dream) is the practice of interpreting dreams as oracular messages. One of the most ancient mantic forms: present in Mesopotamia, Egypt (Joseph and the dreams of Pharaoh, Genesis 41), the Bible (Daniel and Nebuchadnezzar), Homer, and modern psychoanalysis (Freud, Jung).
Freud vs Jung
Freud (Interpretation of Dreams, 1900): dreams are repressed desire fulfillment. Jung: dreams are messages from the collective unconscious through archetypes.