Demon



"Demon" (sometimes spelled as "daemon") is a term used to describe certain fictional, supernatural beings that appear in several religions and mythologies. Demons are often described as malevolent or self-motivated; in the West, they are usually considered "fallen angels", and seek to ruin God's creation. This goes back to the mythological story of the fall of Lucifer, the former chief angel.

Demonology
Demonology is the general term for the "study" of demons in any religion. Demons, in the broadest sense, are simply supernatural creatures or beings that are not worshiped. Jinns, for example, would be a subject of Islamic demonology; they can be good or evil. In Judaism, are said to follow the dead; in the 13th century, Rabbi  wrote that one should not seal up windows completely because it traps them in the house, so beware entering a pressurized airplane, submarine, space ship or fallout shelter, and closing the window during winter or when driving. In Western culture, and especially Christianity, the word demon usually connotes evil. Demonologists are theologians who specialize in making stuff up studying demons.

Demons in the West
The stereotypical Western image of a demon is (usually) a humanoid with red or black skin, horns, a forked or spiked tail, goat hind limbs as legs, carrying a trident, and sometimes bat-like wings (compare the feathery wings often ascribed to angels) which has been said to have been inspired by pagan deities of similar looks as Pan and Cernunnos. Most of this, however, comes from Medieval times and before on they'd have different looks as hind lims of birds or horses ; other forms exist as Satan as the seven-headed red dragon appearing in the Book of Revelation as well as in drawings, artwork, and fictional universes. Cantos 21 and 22 of Dante's Inferno describe a whole gang of demons, armed with hooks and pitchforks to keep the souls of corrupt politicians immersed in boiling tar.

Demons are sometimes blamed for the ills of the world or its inhabitants. Notably, among Fundamentalist Christians, e.g. in the Bible Belt of America, there are some who prefer to blame their shortcomings on demons rather than the fact that a person may just have a worldly problem; this can be in the form of a demon interfering with the world or a demon possessing an individual. Examples include criminals blaming their actions on demonic influence, the sick blaming their illness on demons, or addicts blaming their habits on demons at the expense of acknowledging their own responsibility. Normally, the prescribed cure for the above conditions would be professional help, but in places where these ills are blamed on demons, it may be prayer or other rituals; in severe cases of "demonic possession" (which in reality could be a mental illness such as schizophrenia), an exorcism may be performed. While both prayer and/or exorcism can lead to a placebo effect, they often do more harm than good by leading to extra stress for all concerned and prolonging the time it takes for someone to get the help they need. They can also cause positive harm to the afflicted, as exorcisms are sometimes violent and/or abusive depending on how they are performed.

In short: Blaming a person's problems on a demon is Not A Good Idea™, especially if the problems may require medical attention.

It almost goes without saying that Fundies love to identify the deities of other religions, especially those mentioned in the Bible, with demons in disguise.

Elsewhere

 * In Greek mythology, daemons were benevolent or evil nature spirits that protected men. The usage of the term daimōn in the New Testament's Greek text supposed the application of said word to the evil spirits of Judeo-Christian tradition.
 * Likewise, the ancient Mesopotamians believed there were both good and bad demons, the latter of which caused sickness and disease. Curing someone's sickness meant driving out those demons. For example, in the  the writer suggests offering the evil demons a piglet, as a substitute for the afflicted.
 * In traditional Chinese mythology, demons, called yaoguai (妖怪) there, are very much a part of the working of the world.  They usually serve as members of the cosmic hierarchy.
 * Fiction is rife with demons; as they often personify evil, they can make excellent antagonists. TV shows such as Buffy The Vampire Slayer and Reaper use demons frequently. They are often used to comical effect, such as mean looking, horned, tailed and winged demons talking normally or joking as if they were just normal people.
 * A more light-hearted and less literal use of blaming demons for ills would be blaming gremlins, such as computer gremlins causing a server to go down for an unexplained reason. This is usually more a figure of speech than an actual belief that a creature is there messing about with the world. Gremlin mythology originated with British pilots in the 1920s, who blamed gremlins for sabotaging their aircraft. The gremlin spread into wider pop culture during World War II and many Looney Tunes cartoons of the era feature gremlins. Gremlins even made an appearance or two on The Twilight Zone, haunting Captain Kirk Bill Shatner on an aircraft.
 * In UNIX and other computer multitasking operating systems, a daemon is a computer program that runs in the background, rather than under the direct control of a user; they are usually initiated as background processes. Typically, daemons have names that end with the letter "d": for example, syslogd, the daemon that handles the system log, or sshd, which handles incoming SSH connections. In the Windows world, the equivalent of a daemon is called a service.
 * Clergyman Donald Crosby protested a local high school's mascot, which was a demon—selected to honor a World War II fighter squadron, the "Screamin' Demons". Sigh.
 * Remember that demons are not devils and vice versa if you're in Dungeons and Dragons, if you do not want to have still more trouble than what you'll more than likely have when dealing with them.