Dream is what we experience, see, and feel during sleep. But why is it caused? Whether it has some purpose or not, is not fully answered by anyone yet. At present, there are two groups who explain the answer to such questions as per their own perspective. But in some points, both are the same as dreaming takes place during REM, or rapid eye movement, sleeping phase, etc.
In 1977, J. Allan Hobson and Robert McClarley gave the activation synthesis model of dreaming. Accordingly, during REM sleep our brain gets activated and causes the areas of limbic system, amygdale and hippocampus involved in emotions, memories, sensations, etc. which result in dreaming. Finally, our brain synthesizes and interprets this internal activity in signals.
As per Hobson, dreams are never meaningless but whether it is truth or not, no one knows till now.
