Yes, you are correct. Boromir, as portrayed in J.R.R. Tolkien's books "The Lord of the Rings," is indeed different from his portrayal in Peter Jackson's film adaptation. The differences primarily stem from the adaptation process and the medium through which the characters are presented.
In the books, Boromir is a complex and multidimensional character with a rich inner conflict. He hails from Gondor, a noble and proud realm in the south of Middle-earth, and he is the eldest son of Denethor II, the Steward of Gondor. Boromir is a valiant warrior and a skilled leader, but he carries the weight of his responsibilities and the fear for his people's safety. His main desire is to defend Gondor against the threat of Mordor and the growing power of Sauron.
However, Boromir is also tempted by the One Ring's power, which Frodo carries on the quest to destroy it. The Ring exerts a corrupting influence on those who come into contact with it, and Boromir's inner struggle to resist its allure is a significant part of his character arc in the books.
In the films, due to time constraints and the need to streamline the narrative, some of the depth and complexity of Boromir's character were condensed and altered. While the core elements of his story remain, the film portrays him more as a brave but flawed hero, with less emphasis on the internal struggle against the Ring's influence. This portrayal simplifies his character, making it easier for the audience to understand his role within the context of the movie's plot.
Additionally, in the books, Boromir's relationship with his younger brother Faramir is explored in more detail, providing further insight into his personality and family dynamics. Unfortunately, due to the limitations of movie runtime, some of these nuances were diminished or excluded from the film adaptation.
In conclusion, the differences between Boromir in the books and the movies are mainly due to the challenges of adapting a complex and expansive literary work into a cinematic format. While the core essence of Boromir's character remains intact, the films necessarily present a more streamlined and focused version of him, while the books delve deeper into his inner struggles and personal journey.