Prophets mentioned in the Bible, given the word directly from God, could have been said to have been precogs. Only, somehow, the Word of God vs. something a person perceives as a future event without the WOG doesn't have as much gravitas, so let's not deal with prophets. Besides, it's a little difficult separating WOG details from regular, run of the mill precognition by ordinary people not in God's pipeline.
It is also difficult to separate ordinary people with a gift from people locked up in mental institutions who hallucinate or are just plain over the edge.

A precog sees events that will happen at a future time. Not minutes away, days, maybe years away. And it isn't your mother saying, "If you don't get good grades, you'll flunk out of college." That's just cause and effect. Bad grades=failure. It's your mother "seeing" you climbing a mountain and planting a little flag on top while wearing a space suit.

It may take years for it to happen, and a whole lot of science going on in between. Usually, she'll forget the vision or die in the amount of time it takes for this event to actually happen, but if she's clever and has written it down, she's a precog. Just a dead one.

This gift, unfortunately, is one that is extremely difficult to prove.
It's sort of an "I told you so" thing, unless the vision is written or told to several witnesses. Kennedy being shot? Lots of people "saw" it, supposedly. Several tried to prevent it, but were too vague or couldn't get through to the president of the US.

He died.

Afterward, when all the books came out that listed his assassination as one of the sensitive's predictions, well. Ex post facto.
But, the vision of a future event. It comes in clear as crystal, as if you're seeing it on television, or you are in the room with those who will witness the event. It can come in a dream, in the resting or meditative state, or when you're washing dishes at the kitchen sink or driving in your car. The event takes place in the precog's mind, the whole picture, the whole show, detailed in every possible way.

And, if this is the first time this has happened, the individual won't know what the heck they're dealing with. No chance to warn anybody, usually, because nobody will listen.
The event usually involves someone in the family or someone famous. If the vision involves someone the sensitive doesn't know, that could make the whole vision worthless until the news comes on television and the precog smacks his/her forehead and says... I saw that happen.

This isn't just intuition. <> is a feeling that something good or bad will happen, given the ability to get the elements of a situation and draw conclusions that goes beyond what is rational or what anyone would conclude. You see a kid riding a bike. He isn't wearing a helmet. You know in your head that that's dangerous and he might get hurt. That's just common sense.
You see a kid who has been warned repeatedly that he should wear a helmet while riding his bike and you know that in the future, he'll be a reckless little SOB and will need watching to protect his life from accidents and situations where he will be prone to danger...that's intuition.
You see him killed by a drunk driver in detail, every instant of the accident. The kid's older and you know exactly where it happens, you see the accident, the car striking him, him flying through the air, how many bones are broken...that's precognition.