Dystopian literature is a genre of fictional writing used to explore social and political structures in ‘a dark, nightmare world.' The term dystopia is defined as a society characterized by poverty, squalor or oppression.
The most popular definition of dystopian literature is that it is anti-Utopian. The genre challenges utopia's fundamental assumption of human perfectibility, arguing humanity's flaws make it impossible to construct perfect societies. Dystopian literature is deliberately written to frighten the reader.
(https://www.questia.com/library/literature/literary-themes-and-topics/dystopian-literature)