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Such teams could be selected to play in a match against an opposing team, to represent a football club, group, state or nation, an All-star team or even selected as a hypothetical team (such as a Dream Team or Team of the Century) and never play an actual match.
There are several varieties of football, with the most notable being Association football, Gridiron football, Australian rules football, Gaelic football, rugby league and rugby union. The number of players selected for each team within these varieties and their associated codes can vary substantially. In some, use of the word "team" is sometimes limited to those who play on the field in a match and does not always include other players who may take part as replacements or emergency players. "Football squad" may be used to be inclusive of these support and reserve players.
The term football club is the most commonly used for a sports club which is an organised or incorporated body with a president, committee and a set of rules responsible for ensuring the continued playing existence of one or more teams which are selected for regular competition play (and which may participate in several different divisions or leagues). The oldest football clubs date back to the early 19th century. The word team and club are sometimes used interchangeably by supporters, although typically refers to the team within the club playing in the highest division or competition.
Variation of player numbers among football codes 
The number of players that take part in the sport simultaneously, thus forming the team are:
- Association football: 11
- Indoor soccer: 6
- Futsal, beach soccer, five-a-side football: 5
- American football: 11
- Arena football: 8
- Canadian football: 12
- Rugby league: 13
- Rugby union: 15
- Rugby sevens: 7
- Gaelic football: 15
- Australian rules football: 18
Lists of association football teams 
- List of association football clubs
- List of men's national association football teams
- List of women's football clubs
- List of women's national football teams