Though not specified anywhere within the rule books that there are certain positions which must be filled on the court, basketball has evolved into a very structured game where such positions have become an integral part of the game. Throughout the years, the positions have become more specific. During the first fifty years of the sport, teams generally populated the court with two guards, two forwards, and one center.

In the 1980's the positions became more clearly defined, being renamed as five separate positions. The five men on court were now the point guard, the shooting guard, the small forward, the power forward, and the center. In certain plays, the center may be replaced with a third guard for a "three guard offense".

There are two major defense strategies employed by professional basketball teams, one being a zone defense and the other a man-to-man defense. The zone defense strategy calls for players to maintain certain positions on the court and guard whichever player from the other team enters their "zone". In a man-to-man defense, each player is assigned a specific opposing team member to guard and follows his actions all over the court in an attempt to keep his actions under control.