Most people dream, some people chase and realize their dreams. Understanding dreams however is the key. A dream can be defined as experience of voices, events etc in our imagination or in mind. Oneirology is the study of dreams in humans. Human history is riddled with instances where dreams have been studied scientifically or have been a source of inspiration for artists as well. What is lesser known fact is that even animals dream.

What is dream Interpretation?

When meanings are assigned to dreams, this process is called Dream Interpretation. Different systems of dream interpretation have assigned meanings like in terms of future events, in terms of chance events during the night etc.

Many scientific researches have been made on dreams and these modern theories have more or less tried to explain as many facts found in scientific research like:

The cause of dreams
The purpose of dreams
The content of dreams
The varying frequencies of dreams
The relationship between dreams and depression
The possible evolutionary role of dreaming

Definition of dream:
Hall
Calvin S. Hall developed a theory of dreams in1953, in which he said that dreaming is a cognitive process. Dream was simply a thought or sequence of thoughts that occurred during sleep, and that dreams are just visual representations of your personal conceptions. According to his explanation, if you dream of being attacked by your friends, this may be a manifestation of fear of friendship.

Sigmund Freud
Freud first published his book The interpretation of Dreams at the end of the 19th century. He had a different concept. He said that the foundation of all dream content is the fulfillment of wishes, conscious or not and the schism between ego and id leads to censorship of dreams. He said that only an understanding of the structure of the dream-work can explain the dream.

Freud listed four transformations applied wishes in order to avoid censorship:

Condensation one dream object stands for several thoughts
Displacement a dream object's psychical importance is assigned to an indifferent dream object
Representation a thought is translated to visual images
Symbolism a symbol replaces an action, person, or idea

According to him these transformations help to disguise the latent content. Nightmares represented a clash between the ego and the id: the id wishes to see a past wish fulfilled, while the ego cannot allow it; he interprets the anxiety of a nightmare as the ego working against the id. Freud did a lot of research self analysis and psychoanalysis on his patients before arriving to this conclusion.

Scientific American-theory:
Later many people also did a lot of research on dreams .A theory was put forth in 2003 on the Scientific American, according to which dreams provide sensory stimulation to the brain when the eyes, ears, etc. are still developing. Tests showed that REM-deprived cats developed visual problems. Analysis showed that there is a direct correlation between immaturity of an animal at birth and its required REM sleep like for example, the platypus, which is born without eyes cling to its mother for weeks and they need the most REM of all mammals; where as the dolphin, which at birth is a self-sufficient swimmer, gets almost none.

It also suggested that since humans wake more quickly from REM than normal sleep, dreams could have evolved to keep us alert for predators in the night. According to this theory nightmares could be a specialized form of this; a human makes a sudden, reflexive movement when he is woken up from a nightmare, which can collide with a beast that would otherwise have killed him.

Oneiromancy:
Dreams are also considered as a prediction of the future-oneiromancy or messages from the past and so people tend to interpret their dreams according to what they believe could happen or the object they see could mean of something. They look for signs to get their interpretations right.