Sleep Disorders: Medical disorders of the sleep patterns. Night terrors can be considered a type of sleep disorder - like a 'horror movie' that keeps playing on repeat.
Parasomnias:These are abnormal behaviors such as nightmares or sleepwalking that occur during sleep. It's like acting out scenes from the 'movie' in your sleep.
Nightmare: A disturbing dream associated with negative feelings, such as anxiety or fear. This is another kind of 'scary movie', but unlike night terrors, you usually remember the plot when you wake up.