A prequel is an installment that is made following the original product which portrays events occurring chronologically before those of the original work. Although its name is based on the word sequel, not all prequels are true sequels that are part of a main series. Prequels that not are part of a main series are called spin-off prequels, while prequels that are part of a main series are called true prequels. An example of a true prequel is Tremors 4: The Legend Begins which took place chronologically before the events of the previous Tremors films. Another example of a true prequel would be Better Call Saul, taking place mainly before Breaking Bad but also having some scenes after and during it.
