Football is a family of team sports that involve, to varying degrees, kicking a ball with a foot to score a goal. Unqualified, the word football is understood to refer to whichever form of football is the most popular in the regional context in which the word appears. Sports commonly called football in certain places include: association football (known as soccer in some countries); gridiron football (specifically American football or Canadian football); Australian rules football; rugby football (either rugby league or rugby union); and Gaelic football. These different variations of football are known as football codes. In 1888, The Football League was founded in England, becoming the first of many professional football competitions.
Common elements: The various codes of football share certain common elements: Players in American football, Canadian football, rugby union and rugby league take up positions in a limited area of the field at the start of the game. They tend to use throwing and running as the main ways of moving the ball, and only kick on certain limited occasions. Body tackling is a major skill. Association football and Gaelic football tend to use kicking to move the ball around the pitch, with handling more limited. Body tackles are less central to the game, and players are freer to move around the field. Common rules among the sports include:
- Two teams of usually between 11 and 18 players; some variations that have fewer players (five or more per team) are also popular.
- A clearly defined area in which to play the game.
- Scoring goals or points by moving the ball to an opposing team's end of the field and either into a goal area, or over a line.
- Goals or points resulting from players putting the ball between two goalposts.
- The goal or line being defended by the opposing team.
- Players being required to move the ball—depending on the code—by kicking, carrying, or hand-passing the ball.
- Players using only their body to move the ball.
In all codes, common skills include passing, tackling, evasion of tackles, catching and kicking.
Football in India: Football is a popular sport in India. Football has enjoyed popularity in West Bengal, Goa, Kerala, and north-eastern India which consists of Assam, Manipur, Meghalaya, Mizoram, Nagaland, Tripura, Arunachal Pradesh and Sikkim. The All India Football Federation, which runs the game in India, was formed in 1937, but took more than a decade to get affiliated with FIFA (Fédération Internationale de Football Associatio or "International Federation of Football Association")
- I-League: National Football League, established in 1996 by governing body All India Football Federation (AIFF) was the first "semi-professional" football league in India. The League was renamed and restructured and the I-League was founded in 2006 after India's former top league the National Football League disbanded in a successful effort aimed at increasing the game in India. The I-League is contested between 14 clubs each season.
- I-League 2nd Division: The I-League 2nd Division ranks second in the hierarchy of Indian football since the disbanding of India's top league in 2005. The I-League 2nd Division has 21 member clubs evenly divided among three divisions.
- State League football: State league football is considered the best amateur leagues in India. Each state has their own league in India. There is no promotion/relegation between the state leagues and the I-League 2nd Division but there could be promotion/relegation between leagues within the state.
- Calcutta Football League: Calcutta Football League (CFL) is the football league system where several football clubs of the Indian city of Kolkata (Calcutta) participate. It currently consists of six-tier pyramid system. Indian Football Association (IFA) conducts the CFL with 157 mostly Kolkata based clubs and units. Started in 1898, this league is the oldest league in Asia and one of the oldest in the world.
- Youth leagues: Right now the official youth leagues in India are I-League U18 and U16 Youth league. I league U18 started as U19 tournament in 2011. AIFF started U16 Youth League in 2015 in the wake of 2017 FIFA U-17 World Cup (hosted by India).
- Indian Super League: The Indian Super League, a tournament just recently recognized by AFC or FIFA, was founded in 2013 in an effort to make football a top sport in India and to make Indian football a major player worldwide. The league operates along the lines of the Twenty20 cricket Indian Premier League, and Major League Soccer of the United States. Unlike the vast majority of football leagues around the world, the ISL does not use the promotion and relegation system. Instead, it uses an American style franchise system in which ten teams were specifically created to participate in the league. Each team in the ISL is composed of players from I league or state league, apart from the foreigners who may or may not be a part of the I league. Recently it was recognised as the second national league in India, which means ISL champions from 2017-2018 leagues will be eligible for an AFC Cup qualifying slot[
- Federation Cup: The Federation Cup (abbreviated as Fed cup) is an annual knockout style club football tournament in India. It has started in 1977. Presently it is the most important club tournament after I-league. Winning club of Federation cup gets a chance to compete in the continental level in AFC Cup along with I-league champion team.
- Durand Cup: The Durand Football Tournament was started by then, India's Foreign Secretary, Mortimer Durand at Simla, India, in 1888. The Durand Cup was twice suspended, during the two world wars. In 1940 the venue was shifted to New Delhi.
- Indian Super Cup: The Indian Super Cup was a one-off annual Indian club association football match contested between the I-League champions and the Federation Cup winners.
- Santosh Trophy: Santosh Trophy is an annual Indian football tournament which is contested by states and government institutions.
- IFA Shield: The IFA Shield is an annual football competition organized by the Indian Football Association. It is the fourth oldest club cup competition in the world (Started in 1893) after the English and Scottish FA cup's and the Durand Cup.
Qualification for Asian competitions:
- AFC Cup: The champions of Indian Super League and Champions of I-League qualify.
- AFC Champions League: The Champions of I-League qualify.
National team: The India national football team is the national football team of India and is governed by the All India Football Federation. It is a member of the Asian Football Confederation.
The game in India is administered by the All India Football Federation (AIFF), which is affiliated with the regional Asian Football Confederation, as well as with the worldwide body FIFA. The Indian national team has entered into the regional Asian Cup but has never competed in any World Cup. The Indian women's national team has also played in various competitions; moreover, women's football has its own separate inter-state and state competitions. Youth football is administered by the governmental Sports Authority of India.
Women's football: Women's football has not had the relative head start over the rest of the world that the men's game has had, and also has not had the chance to spread through the country like its male counterpart. The game was administerd by the Women's Football Federation of India (WFFI) from 1975 until the early 1990s when they were absorbed into the AIFF. The women's game, like the men's game, also has its early pioneers in the state of West Bengal. The large Kolkata teams, East Bengal and Mohun Bagan, started women's club sides in the 2000–01 season, and they participate with other teams in the Calcutta Women's Football League. The women's national competition is played on a state vs. state basis in the India women's football championship. There are also similar national championships for junior teams like the Junior Girls National Championship (for under 19s) and the Under-17 Girls National Championship.