Slaughterhouse-Five is a postmodern, contemporary fiction novel written in 1968 and published in 1969. It belongs to the genre of science fiction, with Billy Pilgrim traveling through time and encountering the Tralfamadorians, an alien species.
There are autobiographical fiction elements to the story as well, most notably through the narrator as a stand-in for Vonnegut himself. Vonnegut, like the narrator, fought in World War II, was a prisoner of war at Dresden during the bombing, and taught at the "famous Writers Workshop at the University of Iowa." Indeed, Vonnegut's experience in World War II generally and at Dresden specifically heavily informs the details of the story and its broader anti-war message. Moreover, the narrator often interjects into the fictional world of the story to claim something really occurred or to take credit for making a specific comment. These autobiographical elements juxtapose nicely against the science fiction elements in the book, somewhat grounding the otherwise unrealistic science fiction claims.
Slaughterhouse-Five is one of the most famous anti-war and World War II novels. Although World War II is the subject of the story, it is equally a commentary on the Vietnam War, which was happening as the book was written and published. It then belongs to the sub-genre of war fiction, drawing on the real-life experience of Vonnegut as discussed above.