RPGMemes

Correct. To be more specific, in Tolkien lore, Bilbo (and later Frodo adding to it, organizing it, and editing it) wrote the “Red Book of Westmarch” which was later translated by the narrator of the books into the Hobbit and Lordnof the Rings. Many (most?) Tolkien fans prefer to frame things this way when discussing the stories, and for good reason— that’s how Tolkien himself viewed the stories. As a translation of something in another language. He was a linguist, after all.

Wikipedia has a good article on it: https://en.wikipedia.org/wiki/Red_Book_of_Westmarch