The term "goalposts" refers to a set of vertical poles with nets attached, used in various sports such as soccer or football. The goalposts mark the area where players attempt to score points by getting the ball into the net. In a broader sense, the phrase can also be used metaphorically to refer to something that is constantly moving or changing, making it difficult to achieve a specific outcome. For example, "the goal posts keep shifting" could mean that the criteria for success are continually being redefined and make it challenging to reach a clear objective.