In golf, you can't have an unlimited number of golf clubs in your bag. You can only play with a certain number of golf clubs throughout the course of a round.
Since 1938, golfers are allowed to carry a maximum number of 14 golf clubs in their bag during a round. The Rules of Golf don't say specifically which clubs a player must have in their bag. There's only a limit on the maximum number: 14. Most people typically go with a driver, a fairway wood or two, a hybrid or two, between six and seven irons, a few wedges or three, then a putter. But they all must add up to no more than 14 clubs.
Otherwise, a player can be given a two-stroke penalty for each hole (up to two holes) in which they carry over the limit. So, if a golfer has 16 clubs in their bag -- just in the bag; they don't have to be used to incur the penalty -- for two holes (or more), then that golfer incurs an eight-stroke penalty. That means it's very important to count the number of clubs you have in your bag before a round begins and take out any clubs you don't need above the 14-club limit. If you break a club during a round by doing normal golf activities (as opposed to over your knee or tomahawking it into the ground), then you can replace that club with a new one without penalty.
While there is a maximum number of golf clubs a golfer can carry in their bag, there isn't a minimum. Golfers can carry a single club if they wish to complete a round of golf, so long as it conforms to the rules and equipment standards of the USGA and R&A, which handle the Rules of Golf and determining if equipment producing meets their standards and regulations. Most commonly, golfers will carry three or four clubs in their hands for a nine-hole course or just as a unique challenge of getting around an 18-hole course. There are also smaller golf bags, colloquially known as Sunday bags, which carry seven or eight clubs that give players something lighter to carry with less equipment.
It's probably worth answering why there's a 14-club limit at all. For literally centuries, there weren't rules in golf about a maximum number of clubs. In 1934, Lawson Little won the British Amateur -- then one of the four biggest tournaments in the world -- with 21 clubs. Francis Ouimet won the 1913 U.S. Open with just seven. Back then, equipment production was more scattershot and the clubs were inconsistent in practically every way. No two drivers were even close to alike, or any other club for that matter. So the idea of having a limit of clubs seemed silly; you played golf with the clubs you knew, even if that meant having 20 or 30 clubs in your bag.
Over time, however, caddies, who were often carrying two bags at once, would be lugging extremely heavy loops and it hurt the game. Hence, the limit.