Precognition is the ability to see events in the future, and before they happen. And it is without the use of conventional sources.
For instance, the weather forecast has nothing to do with precognition. Here, mathematics and statistical models are used to predict the future weather.
To warn about an earthquake or an airline crash, is something different. One cannot have any knowledge about this on the beforehand.
But precognition can also be more modest warnings, like the feeling the car is going to break down tomorrow.

The precognition often comes to the person in form of a dream, daydream, or an actual form of paranormal event.
Only on very few occasions, the subject has the ability to change the outcome of the warning.

Certainly, the best known person, to see into the future, would be the Frenchman Michel de Nostradame (Nostradamus). He lived 1503 – 1566 and some believe he was able to see the coming of the plague, 1st and 2nd World War, the murder of John F. Kennedy, the atom bomb and the coming of a 3rd World War.
Nostradamus wrote, that he would look into water or a flame. Then, his visions would arrive.