Robinson Crusoe, written by Daniel Defoe, is a novel. A novel is a genre defined as a long imaginative work of literature written in prose. In other words, it is fictional rather than based on a true story and is written in prose rather than verse.
One can also talk about "subgenre" or what type of novel it is. First, it is a type of travel fiction, set in an exotic local. Next, it is a realistic story, rather than a fantasy or romance, in that it describes relatively plausible behavior by an ordinary person rather than heroic acts of someone with supernatural powers.
In some ways it resembles a spiritual autobiography, as it shows the development of the religious and spiritual thought of its protagonist, but it is not autobiographical per se because it is fictional and autobiography is factual.