Fairy tales and fables are known as didactic stories---they are written with the intent to teach something to readers. You can recognize these stories because they always end with the characters learning a lesson about bad behavior. Aesop's Fables, such as "The Hare and the Tortoise" and "The Dog and the Shadow," are classic examples of this type of story. The lessons learned in fables such as Aesop's, lessons like "slow and steady wins the race," are simple and timelessly applicable to life.
Are your children excited by stories of space travel, robots and psychic powers? Science fiction, part of a larger genre known as speculative fiction, is a rich genre filled with fantastic stories about situations that might possibly happen at some point in the future under specific circumstances. This genre is an exercise in speculation, and can be summed up by the question "What if?" If your child has a vivid imagination, then science fiction will certainly be appealing. A good example of this genre is Orson Scott Card's "Ender's Game," a story about an exceptional young boy recruited for a military academy that trains generals for space battles.
Fantasy is a fiction genre that incorporates fantastic themes, often involving subjects such as magic and talking animals. Like fairy tales and fables, fantasy stories for children often include some sort of life lesson for children to take away from the story. "Charlotte's Web" is a well-known example of a fantasy story with a moral message, namely one of loyalty and loving friendship. Children enthralled by magic tricks will find themselves drawn to fantasy tales such as the Harry Potter series.
Realistic fiction combines realistic characters and situations. These stories focus on the trials and tribulations of children placed into hardships of some kind, and allow children to easily relate to the characters in the stories. Sherman Alexie's "The Absolute True Diary of a Part Time Indian" is the story of a young American Indian boy who takes the bus every morning to go to the school off his tribe's reservation. It is a prime example of the sort of social issues this genre deals with. This genre speaks well to children who have recently moved or find themselves in a situation that has them struggling to adjust.