Golf worldwide is governed by bodies reflecting the interests of both amateur and professional golfers.
The game's very best professional players compete on full time tours - the two biggest being America's PGA Tour and the PGA European Tour.
Golf's four biggest championships are referred to as Major Championships. Three of them are played in the US - the US Open, US Masters and USPGA - with the fourth and oldest, the Open, staged in Britain or Ireland.
Winning any of these just once is regarded as the pinnacle of achievement for a professional golfer which makes Jack Nicklaus's record of 18 Majors all the more remarkable.
Top amateur players also compete to a high standard both nationally and internationally with the Walker Cup the equivalent of the Ryder Cup for Tour stars.
The R&A, which organises the Open Championship, is responsible for the Rules of Golf that all players, both professional and amateur, play to worldwide (with the exception of America and Mexico).
In America and Mexico the United States Golf Association (which works closely with the R&A) is responsible for the Rules of Golf.
Professional bodies in the UK include The Professional Golfers' Association (incorporating the WPGA), PGA European Tour and Ladies European Tour.
In America the main professional bodies include the PGA of America, PGA Tour and Ladies Professional Golf Association Tour.
At amateur level, the leading body in world golf is the R&A while in the UK, the Home Unions and Ladies Golf Union also play prominent roles in the organisation of playing opportunities.