Difference between Dream and Nightmare

Key difference: A dream means the successive images, events and sensations that a person experiences in his/her sleep. A nightmare too is a dream, albeit an unpleasant or frightening one at that.

Dream Dreams are a fascinating subject of debate indeed. In their dreams, people experience many kinds of images, events, or feelings that compel them to introspect deeply about their personalities. Dreams have no definite plot or a set formula that they work on. No person has the same dream repeatedly. Dreams can range from being funny to being action-packed, thrilling, highly emotional, strange, abstract, or even horrifying at times. Dreams are like watching movies with closed eyes, where you play the protagonist.

A nightmare means a bad dream. Of all the types of dreams possible, nightmares are often dreaded as they’re very unpleasant to experience. Children often complain of seeing frightening monsters and aliens in their dreams, which is a prime example of a nightmare. Adults too have nightmares in various ways. For instance, an employee may have a nightmare about his boss firing him. Nightmares can range from simple ones like these, to even complex ones like a person attending his/her own funeral, etc. Like dreams, many scientists and psychologists have tried to make sense of nightmares, but to no great avail.

Comparison between Dream and Nightmare:

	Dream	Nightmare
Meaning	A dream means the successive images, events and sensations that a person experiences in his/her sleep	A nightmare too is a dream, albeit an unpleasant or frightening one at that.
Sleep duration	People are able to wake up as their body clock	People experience prolonged sleep due to stress and trauma
Types	Dreams can be abstract, funny, emotional, romantic, etc.	Nightmares are mostly scary and terrible.
Memory	People do remember dreams that they enjoyed, or intrigued them.	Since nightmares are dreadful, most people choose to forget about them, maybe even instantly after having a nightmare.