The USGA Handicap System™ enables golfers of all skill levels to compete on an equitable basis.
Having a Handicap Index® is important. There are links to "The USGA Handicap System" manual and a Course Handicap™ calculator to allow players to convert their Handicap Index to the Course Handicap for any course that has been properly rated.
A basic premise underlies the USGA Handicap System, namely that every player will try to make the best score at each hole in every round, regardless of where the round is played, and that the player will post every acceptable round for peer review. – The USGA Handicap System Manual