Definition of Dreams
Dreams occur as mental activity during specific stages of sleep, often just before awakening.
They reflect altered states of consciousness, including hallucinations, delusions, disorientation, emotional variability, and amnesia.
The proportion of dreams during different sleep stages:

History of Dream Comprehension
Lucid Dreaming
This video explains the process, pros, and cons of lucid dreaming:
Dream Manipulation and Novelty
Dreaming as Emotional Therapy
REM sleep can fail in PTSD patients due to elevated noradrenaline, preventing emotional recovery.
This video introduces a way to stop nightmares and return to restful sleep with the Dream Completion Technique:
Dreams are the time in our life when we're creating new neural connections and processing the experiences we've had in our waking life.
— JESSE LYON, HYPNOTHERAPIST, AND DREAM INTERPRETER
Dream Interpretation Website
Dream Dictionary – Dream Interpretation & Dream Analysis | Dream Dictionary