Star Wars is a cinematographic science-fictional odyssey created by George Lucas ans belonging to the space opera genre (like Star Trek for example). The saga was originally designed to be a trilogy (Episode IV, V, VI : known as the Original Trilogy). Indeed Lucas made the choice to begin his work with the fourth part of the Star Wars story, more suitable to the limited special effects available at the time.

Chronologically, the first episode was release in 1977 (Episode IV: A New Hope). The next two Episodes (V and VI) were released rather soon after the first one and the end of the sixth one did not suggest a possible sequel. There is actually no sequel to the last Epsiode of the saga but a prelogy (Episode I,II and III)

The story takes place “a long time ago in a galaxy far far away” [from ours] where Good and Evil are struggling against each other. The Good side is embodied the Jedi Order, composed of wise warriors taking advantage of a power called The Force, which provides them with a variety of powers (mainly mental but also physical). The main cause for this everlasting war is the craving for power of dark side of The Force, embodied by Sith Lords who unlike jedi knights, driven by anger, hatred and need for power.

Roughtly speaking the prelogy deals with how a young boy, Anakin Skywalker will slowly but surely become the terrible Darth Vador; while the Original Trilogy focuses his son (Luke) and daughter (Leia) fighting to overthrow their father and eventually defeat The Empire.

Initially Lucas has thought to made 3 trilogies, but finally backed down claiming that the saga was complete with 6 episodes and that he had nothing more the tell after the destruction of the second Death Star.