The bunker gets its name due to its appearance, as it resembles bunkers made during times of war in the past. Bunkers according to the most recent rules of golf are defined as "a specially prepared area of sand, which is often a hollow from which turf or soil has been removed".
Bunkers are usually positioned on the sides of the fairway and are made to punish poor shots. Bunkers are designed to test a gold player's ability to use different clubs (wedge, pitch) and skills to hit the golf ball out of the sand.
There are also many different kinds of bunkers that can be found on golf courses. A cross bunker is a bunker that is positioned to make golf players on a certain hole cross through the bunker on a normal line of play. A greenside bunker is any bunker positioned close to the putting green. Fairway bunkers are positioned on either side of the fairway. Waste bunkers (found on links courses) are major areas of sand, but according to the rules are not technically considered hazards.