Final answer:
Night terrors occur during the NREM phase of sleep, while nightmares occur during the REM phase.
Step-by-step explanation:
Night terrors occur during the NREM phase of sleep. They result in a sense of panic, accompanied by screams and attempts to escape from the immediate environment. Individuals suffering from night terrors often have no memories of the events that occurred and attempts to console them are ineffective. Night terrors are usually short-lived and individuals often fall back asleep soon after.
Nightmares, on the other hand, occur during the REM phase of sleep. Unlike night terrors, individuals experiencing nightmares usually have some memory of the frightening dream. Nightmares can be vivid and disturbing, causing individuals to wake up feeling afraid or anxious. They often occur during the later part of the sleep cycle.