What does Forster say is the difference between a novel and a memoir?

In his discussion of characters, Forster points out that the novelist writes about people, but those people are not real. Even if a novelist is writing about a real person such as Queen Victoria, the person in the novel is like the real person, but not exactly like her. If the book was only about the real Queen Victoria and did not add that unknown aspect of fiction the work would be considered a memoir or history book.