Millions of people around the world experience precognitive dreams at some point(s) in their lives

Some common types of psychic dreams are Dreams of Appartitions, Clairaudient Dreams or Clairsentient Dreams. Other types are Premonition of Precognitive Dreams and Telepathic Dreams.

No. "Precognitive" means fore-knowing, or knowing something ahead of time. Precognitive dreams supposedly predict the future. Hallucinations are different in that dreams occur during one's sleep, while hallucinations occur when one is awake, often when one is feverish or otherwise impaired.

Deja Vu ESP is the feeling of having experienced the present situation before, often associated with extrasensory perception. Precognitive dreams involve dreaming of future events or experiences before they happen. Both phenomena suggest a connection beyond normal perception, but Deja Vu ESP occurs in waking moments while precognitive dreams happen during sleep.

Dreams are rarely precognitive. It is more likely that you are experiencing deja vu, a phenomenon that causes one to feel very strongly that one has experienced something previously, even though that is impossible. People often explain the feeling of deja vu by concluding that one must have dreamt the event before it happened. The only sure way to know that a precognitive dream occurred is to maintain a dream diary that can be referred to when one appears to have a "dream come true."