The description in Redbook for MS-65 ( Mint State 65 ) is this : An Above Average Uncirculated coin that may be Brilliant or lightly toned that has very few contact marks on the surface or rim. This coin has been graded by a professional grading company.
PCI is the name of the company that Graded this coin and placed it in this holder ( known as a Slab ) The company was founded in 1989 and was called Photo Certified Institute (hence PCI) You can find out more by searching PCI Coin Grading and can even send in your coins to be graded