Precognition is the ability to perceive events that will (or may) occur in the future. The ability to make prophecies is a staple of literature, including science fiction. In many tales, particularly tragedies, prophecied events are unavoidable, and those who try to prevent them only bring extra grief upon themselves. Indeed, those who try to avoid a prophecied event often cause the event by their efforts.
In other stories, precognition will indicate which is the most likely path history will take, but that path can be changed by those who have foreseen it.
Precognition in Star Wars
In Star Wars, precognition is an ability associated with the Force; both Jedi and Sith have demonstrated it. Their ability to parry numerous attacks and even deflect blaster shots with a lightsabre is often attributed to a form of precognition. They can also foresee events in the distant future, but usually not very clearly. All prophecies seen in the films have come true, although not necessarily as expected by those who made the predictions.
Precognition in Babylon 5
Only two races in Babylon 5 are known to have any real prophetic ability. The Centauri have an uncontrolled ability to dream about the future, particularly the circumstances of their own deaths, and some Centauri women have more controlled prophetic abilities. Vorlon ambassador Kosh also made seemingly accurate, if cryptic, predictions in a telepathic message to John Sheridan. Minbari prophecies involving the final Shadow War are actually not related to psychic phenomena: they are derived from the memories of a time-traveler.