Basketball is highly suited to viewing by spectators, as it is primarily an indoor sport, played in a relatively small playing area, or "court," with only ten players, and using a large ball which is easy to follow. Additionally, the lack of protective gear makes it easy to see the reactions of the players. It is one of the most popular sports in the United States, and is also popular in other parts of the world, including South America, Europe, Asia, and the former Soviet Union.