Paranormal romance is a subgenre of both romantic fiction and speculative fiction. Paranormal romance focuses on romantic love and includes elements beyond the range of scientific explanation, blending together themes from the speculative fiction genres of fantasy, science fiction, and horror. Paranormal romance may range from traditional category romances with a paranormal setting to stories where the main emphasis is on a science fiction or fantasy based plot with a romantic subplot included. Common hallmarks are romantic relationships between humans and vampires, shapeshifters, ghosts, and other entities of a fantastic or otherworldly nature.
Beyond the more prevalent themes involving vampires, shapeshifters, ghosts, or time travel, paranormal romances can also include books featuring characters with psychic abilities, like telekinesis or telepathy. Paranormal romance has its roots in Gothic fiction. Its most recent revival has been spurred by turn of the 21st century technology, e.g. the internet and electronic publishing. Paranormal romances are one of the fastest growing trends in the romance genre.
Some of the authors specializing in this genre include Dani Harper, Jessica Bird, Kresley Cole, Christine Feehan, Kelley Armstrong, Stephenie Meyer, Karen Marie Moning, Richelle Mead, Lauren Kate, J. R. Ward, Gena Showalter and Jeanine Frost, among many others.
Sources: Wikipedia.org and Goodreads.com