As stated by the Merriam Webster Dictionary, the definition of a "genre" is a category of artistic, musical, or literary composition characterized by a particular style, form, or content. Though books and other works of literature share the same genre, they may not necessarily be remotely close to one another when it comes to stories and characters. For example, a pair of books are 1984 by George Orwell and Lord of the Flies by William Golding. Though initially, the two books don't seem to fit in the same genre, by the end they absolutely do. The two books have their own and separate characters and plot points, but both books are criticizing the people and society. When reading in between the lines, one forgets that these two books come from different authors and are about different things. One only realizes that they share many similar traits and themes, even if the books surrounding those ideas aren't necessarily about the same subjects or take place in the same time period.
Lord of the Flies by William Golding is a simple story at face value. It tells the tale of a group of kids whose airplane crashes on an island somewhere in the Pacific. Ralph is chosen as the leader, while Jack is picked to hunt the food for the group. Eventually separating and fighting, the kids go on arguing about whether or not a beast exists on the island and is looking to kill them. After a long fight with Ralph, a naval officer sees them and takes them back to civilization. At one point in the story, Jack kills a pig and puts its head on a stick as an offering to the "beast." Later, Simon has a vision about the pig head in which it speaks to him. It calls itself the Lord of the Flies, and says that the beast is really the violence in all of the kids' hearts and that it doesn't really exist. Another name for the Lord of the Flies is Beelzebub, also known as the Prince of Demons. The Prince of Demons is more commonly known as Satan.