From The Art and Popular Culture Encyclopedia
In folklore, a zombie or zombi is an animated human body devoid of a soul. In contemporary versions these are generally reanimated or undead corpses, which were traditionally called "ghouls". Stories of zombies originated in the Afro-Caribbean spiritual belief system of Vodou.
Other more macabre versions of zombies have become a staple of modern horror fiction, where they are brought back from the dead by supernatural or scientific means, and eat the flesh (or the cerebral matter) of the living. They have very limited intelligence, and may not be under anyone's direct control. This type of zombie, often referred to as a Romero zombie for the filmmaker that defined the concept, is archetypal in modern media and culture.
Modern zombies, as portrayed in books, films, games, and haunted attractions, are quite different from both voodoo zombies and those of folklore. Modern zombies are typically depicted in popular culture as mindless, unfeeling monsters with a hunger for human brains and flesh, a prototype established in the seminal 1968 film Night of the Living Dead. Typically, these creatures can sustain damage far beyond that of a normal, living human (generally these can only be killed by a wound to the head, such as a headshot) and can pass whatever syndrome that causes their condition onto others.
Usually, zombies are not depicted as thralls to masters, as in the film White Zombie or the spirit-cult myths. Rather, modern zombies are depicted in mobs and waves, seeking either flesh to eat or people to kill or infect, and are typically rendered to exhibit signs of physical decomposition such as rotting flesh, discolored eyes, and open wounds, and moving with a slow, shambling gait. They are generally incapable of communication and show no signs of personality or rationality, though George Romero's zombies appear capable of learning and very basic levels of speech as seen in the films Day of the Dead and Land of the Dead.
Modern zombies are closely tied to the idea of a zombie apocalypse, the collapse of civilization caused by a vast plague of undead. The ideas are now so strongly linked that zombies are rarely depicted within any other context.
There are still significant differences among the depictions of zombies by various media; for one comparison see the contrasts between zombies by Night of the Living Dead authors George A. Romero and John A. Russo as they evolved in the two separate film series that followed. In some zombie apocalypse films from the 2000s, such as 28 Days Later, Dawn of the Dead (2004) and Dead Set, zombies are depicted as being superhumanly quick and nimble, a further departure from the established genre stereotype.