An auteur is a film director whose personal style is so strong that the film feels like *their* work, not just a studio product. You can often guess who made it from the camera, the mood, the kind of story, even the jokes. The word is French for “author,” and English borrowed it for cinema: the idea is that the director is the true “writer” of the film, the way a novelist is the author of a book. Film students still talk about this as auteur theory; it was made famous in French film writing in the 1950s. In ordinary English it is a slightly fancy, cinephile word. People use it with respect for directors like Hitchcock or Miyazaki, but they also stretch it: any director with a recognisable style may get called an auteur, even if critics would argue about how strict the label should be. You almost never use it for the writer of a book — that person is an author.