prequel is a feminine noun that describes a literary, dramatic or cinematographic work reporting past events of a particular work, often revealing the same characters when they were younger.
This word comes from the English term "prequel", which appeared between 1970 and 1975.
The three films from Star Wars (Star Wars in English) entitled "Episode I: Phantom Menace", "Episode II: Attack of the Clones" and "Episode III: Revenge of the Sith" are prequels to the first three (episode IV, V and VI), released in the late 70s and early 80s. Although they were filmed many years later (episode I appeared 16 years after episode VI), the prequels tell stories that took place before those revealed in the earlier films.
Another example of famous prequels is the "The Hobbit", which is a prequel to the trilogy of Lord of the Rings.
When a film is highly appreciated, studios often decide to make prequels that explain important events that happened prior to the first film. This is the example of the movie "The Exorcist" from 1973, and which has two prequels.
There is a story authored by J.K. Rowling that is considered a prequel to the film and book saga of Harry Potter. This narrative tells an adventure by Sirius Black and James Potter. In 2008, this work of approximately 800 words was sold at auction for 25,000 pounds.