The game at the highest level is played on a course with an arranged progression of 18 holes, though recreational courses can be smaller, usually 9 holes.
Each hole on the course must contain a tee box to start from, and a putting green containing the actual hole or cup (4.25 inches in diameter).
Shorter holes may be initiated with other clubs, such as higher-numbered woods or irons.
When the initial shot on a hole is intended to move the ball a long distance (typically more than 225 yards (210 m)), the shot is commonly called a "drive" and is generally made with a long-shafted, large-headed wood club called a "driver".
While many holes are designed with a direct line-of-sight from the teeing area to the green, some holes may bend either to the left or to the right.
This is commonly called a "dogleg", in reference to a dog's knee.
The first 18-hole golf course in the United States was on a sheep farm in Downers Grove, Illinois, in 1892. Every round of golf is based on playing a number of holes in a given order.
A "round" typically consists of 18 holes that are played in the order determined by the course layout.