Many a sci-fi character is an ALIEN, which is a creature from outer space that is not human. Aliens are often featured in science fiction stories and films, and are usually depicted as having advanced technology and abilities beyond those of humans. They are often seen as a threat to humanity, but can also be portrayed as friendly or even helpful. The term 'ALIEN' is derived from the Latin word for 'STRANGER, ' and has been used to describe creatures from other worlds since the 19th century.