Each end of an Australian rules football ground has four goalposts: two taller goalposts and two shorter behind posts.
The two central goalposts define the scoring area for a goal. A goal is scored when the ball is kicked completely through them without being touched by another player. The two outer behind posts mark narrower scoring lanes on either side. A behind is recorded when the ball passes between a goalpost and a behind post, or in several other situations such as a touch to the ball before it crosses the goal line.
This four-post arrangement is a distinctive visual feature of Australian football. The goalposts are positioned at opposite ends of the oval ground, and the scoring spaces are open rather than covered by a crossbar or net.
A common mix-up is to count only the two central posts. Those are the goalposts, but the complete scoring setup at each end includes the two behind posts as well.