Herland is a work of science fiction. In this genre, a scientific "novum"—or some new invention or technological development—often changes the world for good. While science fiction is invested in the new worlds it imagines, it also usually uses those new worlds to say something about the mundane, "real" world. For instance, the biological advent of parthenogenesis, and the way the Herlandians engineer birth control, allows them to create a new world order that helps Gilman comment on the way things work in the early 20th-century United States. By imagining a world in which many of the problems of patriarchy are solved, Gilman allows her readers to sit at a distance from those very problems so that they can finally notice them and consider how to address them.
There is a great deal of overlap between science fiction and utopian fiction. Because it portrays a society separate from the "real" world, in which the inhabitants have solved many of the problems that plague the "real" world, Herland can also be classified as a utopian novel. The word "utopia" is a pun playing on two Greek roots: a utopia is at once an "eu-topos," meaning "good place," and an "ou-topos," meaning "no place." It is a place that is too good to be true. In keeping with the tradition of utopian fiction, which includes works such as Thomas More's Utopia and Samuel Butler's Erewhon, Herland features real-world protagonists who journey to the utopia, observe how things work there, and report home to readers they assume will have a hard time believing such a place exists.
Utopian fiction does not always depict a world so perfect it is immune to all criticism. In fact, especially in the 20th and 21st centuries, writers have often played with the blurry boundary between a utopia and a dystopia, or "bad place." In a dystopia, everything is corrupt, and injustice runs deep. The idea that a seeming utopia could tip easily into a dystopia became especially popular following the rise of 20th-century authoritarian regimes that started out claiming they knew how to create a perfect world but ended up committing atrocities on a mass scale. Gilman wrote Herland as a fairly straightforward utopian novel depicting a feminist, matriarchal society in which everyone is far happier than they are in the real world because they have shrugged off patriarchy. But given the role of eugenics in creating the world of Herland, and Gilman's limited understanding of gender as a strict binary, there is plenty of room for debate among modern readers about just how perfect or imperfect the society she depicts really is.