Night of the Living Dead is a series of seven zombie horror films written and directed by George A. Romero and Cameron Romero beginning with the 1968 film Night of the Living Dead written by Romero and John A. Russo. The loosely connected franchise predominantly centers on different groups of people attempting to survive during the outbreak and evolution of a zombie apocalypse. The latest installment of the series, Survival of the Dead, was released in 2009, with Origins, a prequel film written and directed by Cameron Romero in the works.
Labeled Trilogy of the Dead until Land of the Dead, each film is laden with social commentary on topics ranging from racism to consumerism. The films are not produced as direct followups from one another and their only continuation is the theme of the epidemic of the living dead. This situation advances with each film, showing the world in a worsening state, but each film is independent of its predecessor. This is exemplified by the fact that each movie is set within the era it is filmed, with Land of the Dead being set in modern times with current as of 2005 technology such as game consoles, flatscreen televisions, cell phones and other examples of modern tech. This would not have been possible if the original 1968 epidemic had progressed to the state that Dawn and Day had depicted, as no new technology would have been created. The fifth film does not continue the depiction of progress, but returns to the similar events depicted in the first film in the very beginning of a zombie outbreak. The films depict how different people react to the same phenomenon, ranging from citizens to police to army officials and to citizens again. Each takes place in a world worsened since its previous appearance, the number of zombies ever increasing and the living perpetually endangered, but with each entry being a standalone film that is not directly continuing global events from the previous.Romero does not consider any of his Dead films sequels since none of the major characters or story continue from one film to the next.citation needed The two exceptions are Tom Savinis character of Blades who becomes a zombie in Dawn of the Dead who would be seen again years later in Land of the Dead and the military officer Alan van Sprang who robs the main characters in Diary of the Dead goes on to become a protagonist in Survival of the Dead. ........
Source: Wikipedia