Once you’ve got your idea down, you’ll need to decide what genre you will present this idea as. Your idea may dictate the genre. For example, if I want to tell you the true story of my life, I’m going to write an autobiography. If I want to write about a girl who works from her spaceship as an interplanetary freelancer, I’m probably looking to write a sci-fi.
Other ideas can work with multiple genres. If I just want to tell a tale of finding purpose and friendship, I can make that a contemporary, or I can add in some dragons and dwarves and make it a fantasy.
There are certainly more genres and sub-genres than the ones I’m going to talk about, but these are the main ones.
Non-Fiction: Anything that presents a factual account of a person’s life, an event, a time period, or a particular topic. Even if that truth may be biased or show only one person’s side of a situation.
Biography: A non-fiction account of someone’s life.
Autobiography: A non-fiction account of someone’s life, written by that person.
Memoir: An account of a particular even or time period, told by someone who lived through it.
Self-Help: Advice meant to help people improve themselves and their lives.
Activity Book: Anything filled with activities. Mad libs, crosswords, sudoku, word searches, coloring books. Generally the activities are done inside of the book.
Fiction: Any non-factual story.
Contemporary: Set in the present day real world.
Historical: Set in the past.
Fantasy: Depending on the type, set in a made up world and/or containing fantastical elements such as magic or made up creatures or races.
Epic Fantasy: Fantasy in the classic sense. A grand tale of a hero having to save the fictional world by defeating a villain, usually includes magic, generally includes fictional creatures and races as well.
High Fantasy: Set in a fictional place.
Low Fantasy: Set in the real world, but contains magic or fictional creatures.
Sci-Fi: A fictional story that has fantastical elements based on science. This could mean the story is set in space, contain time travel, multiple dimensions, or aliens coming to earth. These stories are often set in the future.
Paranormal: Containing supernatural creatures, generally ghosts, or supernatural powers, usually psychic in nature.
Horror: Meant to be frightening due to the threat of some monster, be it a creature, a supernatural presence, or a person.
Thriller: Any story meant to be suspenseful and maintain a feeling of anticipation.
Mystery: The main character, and consequently the reader, are trying to solve a mystery as the main plot.
Romance: The main story is based around a romantic relationship.
Graphic Novel: Although any book can contain illustrations, graphic novels, as well as manga, are told primarily or entirely through images.
Age categories are used alongside genre. These are the main ones, there are more for even younger readers, mostly those books are picture books. These categories are definitely not limited to the themes I mention, they’re just examples that show up a lot in each group. Really these are just used to show who the story may appeal the most to and, in terms of reading level and maturity, who the story may be most appropriate for.
Adult: The main characters are adults and the theme is intended for adults. This doesn’t mean it has to be mature or inappropriate for younger readers, but the text is usually denser and the story is generally more relatable for grown ups.
New Adult: This is a newer age category. It’s basically a made up age range within adult that reads a bit younger than typical adult, but is more mature in nature than your average young adult story. The main characters are usually 20-somethings. The story usually overlaps adult themes with a coming of age type theme.
Young Adult: The main characters are teenagers. Meant to be relatable to teenagers, usually contains a coming of age theme with a heavy focus on relationships, this could be family, friendships, or romantic relationships.
Middle Grade: The main characters are children. The story usually focuses on adventure and friendship, although there can certainly be deeper themes included. Meant to appeal to young readers.
Of course any book can fall into multiple genres. If I want to tell a young adult sci-fi romance where the main characters are being haunted by the ghost of an ancient dragon, I can. Genres are used more for marketing than the actual writing process, so don’t feel limited to just one or two while you’re working on your draft. But it can be helpful when you’re getting started to know what sort of setting, theme, and tone you’re aiming for before the writing begins.