What’s the difference between a PR69 coin and a PF69 coin?

Both are high-quality proof coins with a numerical grade of 69 on the Sheldon Coin Grading Scale, meaning they are nearly perfect with only minor imperfections not visible to the naked eye. The only difference is the grading service that assigned the grade. PR is the designation the PCGS (Professional Coin Grading Service) uses to denote proof coins; PF is the designation the NGC (Numismatic Guaranty Corporation) uses.