To paraphrase something means to re-state it in your own words.
For example, here is an exact quote from Wikipedia:
On 31 August 1997, Diana, Princess of Wales was killed in a car crash in a the Pont de l'Alma road tunnel in Paris, France, along with her companion Dodi Fayed, and their driver Henri Paul. Fayed's bodyguard Trevor Rees-Jones was the only car occupant to survive the accident.
If I had to paraphrase this, I might say:
Diana, Princess of Wales, died on August 31, 1997. She and her companion, Dodi Fayed, were killed in a car accident in the Pont de l'Alma tunnel in Paris, France. The driver of the car was also killed; only Trevor Rees-Jones, Fayed's bodyguard, survived the crash.
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