Paradoxical Sleep: Another term for REM due to its paradoxical qualities; despite being deeply asleep our brains are highly active, almost as if we were awake.
Lucid Dreaming:A dream during which the dreamer is aware they're dreaming. These often occur during REM sleep when dreams are most vivid.
Sleep Paralysis:A temporary inability to move or speak while falling asleep or upon waking. This can happen when someone starts to wake up during REM sleep.