Dreams are the images, thoughts and feelings experienced while sleeping, particularly strongly associated with swift eye movement sleep. The contents and purpose of dreams are not fully silent, though they have been a topic of gossip and interest throughout recorded history.

There is no universally granted biological definition of dreaming. General examination shows that dreams are strongly associated with rapid eye movement (REM) sleep, during which an electroencephalogram shows brain commotion to be most like restiveness. Participant-remembered dreams during non-REM sleep are normally more humdrum in comparison. During a typical lifespan, a human spends a total of about six years dreaming. It is unknown where in the brain dreams instigate, if there is a single origin for dreams or if multiple portions of the brain are involved, or what the purpose of dreaming is for the body or mind.

When the body decides that it is time to sleep, neurons near the eyes start to send signals throughout the body. According to Michael Smith, these neurons are located in such close propinquity to neurons that control eyelid big physique that the eyelids begin to grow deep. Glands begin to secrete a hormone that helps induce sleep and neurons send signals to the spinal flex which make the body relax.