The Twilight Saga, despite only having four main books, is considered a saga because:
* It follows a continuous storyline: The books tell a complete story, with events building upon each other and characters developing over time.
* It features a multi-generational aspect: The story spans several years and includes multiple generations of characters, particularly in the later books.
* It delves into complex themes and relationships: The books explore various themes such as love, family, friendship, good vs. evil, and the supernatural.
Therefore, even with only four books, The Twilight Saga possesses the essential elements of a saga: a connected storyline, a span of time, and a focus on character development and complex themes.