Dream interpretation, the effort to draw meaning from the images and events of dreams, is among the most ancient and widespread of human practices, undertaken across cultures as a means of receiving divine messages, foreseeing the future, diagnosing illness, and understanding the self. In many traditional societies dreams were regarded as a genuine channel of communication with the divine or the dead, and their interpretation was a serious religious art. The ancient Mesopotamians and Egyptians kept dream manuals cataloguing the meanings of dream images; the Hebrew Bible records God speaking through dreams and the gift of their interpretation given to figures such as Joseph and Daniel, who read the dreams of kings; and the Greco-Roman world produced elaborate systems of dream classification, most famously the second-century dream book of Artemidorus.
The great religions took varied positions on the practice. Islam developed a rich science of dream interpretation, tabir, distinguishing true dreams that may carry divine guidance from meaningless ones and those from evil sources, and produced a large interpretive literature. In the modern era the interpretation of dreams was transformed by the rise of depth psychology: Sigmund Freud treated dreams as the disguised fulfilment of repressed wishes, a "royal road" to the unconscious to be decoded through the dreamer's associations, while Carl Jung read them as expressions of a deeper psyche communicating through universal symbols and archetypes. These psychological approaches shifted the aim of interpretation from divination about the world to insight into the self, and while the scientific study of dreaming has moved in other directions, the interpretation of dreams, whether as divine message, psychological revelation, or personal reflection, remains a living practice across religious, therapeutic and popular settings.