Well, 'Twilight' is mainly a story about young love in a supernatural setting, with a focus on the love triangle between Bella, Edward, and Jacob. It has elements of vampire and werewolf lore. In contrast, '50 Shades of Grey' which started as 'Twilight' fanfiction, focuses on an adult relationship that involves elements of dominance and submission in a more contemporary, non - supernatural world. The characters in '50 Shades' are also more worldly and complex in terms of their sexual desires and relationships compared to the rather pure - hearted characters in 'Twilight'. Additionally, the overall tone of '50 Shades' is much more sexually charged and darker in some ways than the more romantic and somewhat idealized 'Twilight'.