According to Wikipedia.org, the zombie apocalypse is a particular scenario of apocalyptic fiction that customarily has a science fiction/horror rationale. In a zombie apocalypse, a widespread (usually global) rise of zombies hostile to human life engages in a general assault on civilization. Victims of zombies may become zombies themselves. This causes the outbreak to become an exponentially growing crisis: the spreading “zombie plague/virus” swamps normal military and law enforcement organizations, leading to the panicked collapse of civilian society until only isolated pockets of survivors remain, scavenging for food and supplies in a world reduced to a pre-industrial hostile wilderness.
The literary subtext of a zombie apocalypse is usually that civilization is inherently fragile in the face of truly unprecedented threats and that most individuals cannot be relied upon to support the greater good if the personal cost becomes too high. The narrative of a zombie apocalypse carries strong connections to the turbulent social landscape of the United States in the 1960s when the originator of this genre, the film Night of the Living Dead, was first created. Many also feel that zombies allow people to deal with their own anxiety about the end of the world. In fact the breakdown of society as a result of zombie infestation has been portrayed in countless zombie-related media since Night of the Living Dead. One scholar concluded that “more than any other monster, zombies are fully and literally apocalyptic … they signal the end of the world as we have known it.”
Due to a large number of thematic films and video games, the idea of a zombie apocalypse has entered the mainstream and there have been efforts by many fans to prepare for the hypothetical future zombie apocalypse. Efforts include creating weapons and selling posters to inform people on how to survive a zombie outbreak.