A "doppelgänger" is a term used to describe a person who closely resembles another individual, often to the point of being mistaken for them. The concept originates from German folklore, where it was believed that seeing one's doppelgänger could be an omen of bad luck or even death. In modern usage, it can refer to look-alikes in various contexts, including celebrities or fictional characters. Doppelgängers can also appear in literature and film, serving as a plot device to explore themes of identity and duality. For example, in Robert Louis Stevenson's "Strange Case of Dr Jekyll and Mr Hyde," the characters represent opposing sides of the same person. The idea continues to fascinate people, leading to discussions about the nature of self and the possibility of multiple identities.