Unlike many sports, golf is played for the most part, without the supervision of a referee or umpire. The game relies on the integrity of the individual to show consideration for other players and to abide by the rules.
All players should conduct themselves in a disciplined manner, demonstrate courtesy and sportsmanship at all times, and take necessary steps to care of the course being played on. The word etiquette refers to guidelines on the manner in which the game of golf should be played.
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There are only 24 rules of golf but they have an infinite number of complexities. No one is expected to be an expert in all the rules. However we are all expected to have a basic understanding of the rules.
A good source for all things to do with Rules of golf is the R&A (Royal and Ancient) web site. The R&A - Rules Of Golf (randa.org). There is also an app that allows you to have the rules on your Apple or Android phone for easy consultation if required.
The linked document gives you an idea of some of the basic rules.