Time travel, alternate novels, and rebirth novels were three common types of online literature. The main difference between them was the background and story setting. Time travel novels usually take place in modern times or in the past. The protagonist returns to the past or travels to a different world in some way to change the course of history and unfold a series of stories. Time travel novels often involved time travel, soul travel, and other sci-fi elements. There were also stories similar to "time travel" in "Dream of the Red Chamber," but most time travel novels lacked scientific basis. In a fictional novel, the protagonist entered or transmigrated into the world through some means to explore and experience the world in his own way. The background of fictional novels was usually ancient times, the Middle Ages, or the future. It could also be a fictional world view, a magical world, and so on. Rebirth novels were about the protagonist being reborn at a certain point in time to return to the past or a certain period in the future to change the course of history and unfold a series of stories. The setting of a rebirth novel was usually that the protagonist was reborn at a certain point in time to return to the past or a certain period in the future to start his life again. Rebirth novels often involved family, fate, friendship, and other topics. They were also similar to the "rebirth" storyline in "Dream of the Red Chamber." Time travel, alternate novels, and rebirth novels all had their own unique charms. The readers could choose to read different types of novels according to their preferences.