Here's why:
* Timeline: Episode III takes place 19 years before Episode IV. This means there's a significant gap in the story, with major events occurring in between that are not depicted in the films.
* Characters: While some characters like Obi-Wan Kenobi and Darth Vader appear in both films, they are drastically different. Obi-Wan is a hermit on Tatooine, and Darth Vader is now a powerful Sith Lord.
* Plot: The plot of Episode IV is entirely separate from Episode III. It introduces new characters like Luke Skywalker, Princess Leia, and Han Solo, and focuses on the rebellion against the Galactic Empire.
To understand the connection between Episodes III and IV, you need to consider the following:
* The Rise of the Empire: Episode III depicts the fall of the Republic and the rise of the Empire, with Anakin Skywalker becoming Darth Vader. This sets the stage for the events of Episode IV.
* The Legacy of Obi-Wan: Obi-Wan's role in training Luke Skywalker and passing on the knowledge of the Force connects the two stories.
* The Search for the Rebel Alliance: The events of Episode III lead to the formation of the Rebel Alliance, which is fighting against the Empire in Episode IV.
In conclusion: While Star Wars: Episode IV - A New Hope doesn't directly continue from Episode III, it is heavily influenced by the events of the prequel trilogy, providing the context for the Rebellion and the rise of the Empire.