According to the newest edition of the Rules of Golf, a 'bunker' is a 'specially created location intended to test the player's ability to play a ball from the sand.' Bunkers are holes or depressions in the earth, whether natural or manufactured, that are filled in with sand.

 They used to be categorized as 'hazards' (a term that was deprecated in the 2019 edition of the rule book). Bunkers come in a variety of sizes, shapes, and depths. They are most usually seen guarding putting greens, but they can also be found in fairways and along fairways.

A 'bunker shot' is a stroke played from inside a bunker. Bunkers are also known as traps, sand traps, and sand bunkers. Most golfers interchange the terms 'trap' and 'bunker.' The R&A and the USGA, on the other hand, exclusively use the term 'bunker,' never 'sand trap.'Beach, kitty litter, sandbox, and cat box are all slang terms for bunkers.

The term 'bunker' is one of the oldest in golf, going back to the 1700s. Due to another of its meanings: 'small, deep sandpit in Linksland,' it is likely to have a long history (as defined in The Historical Dictionary of Golfing Terms).