An athletic conference is a collection of sports teams, playing competitively against each other at the professional, collegiate, or high school level. In many cases conferences are subdivided into smaller divisions, with the best teams competing at successively higher levels. Conferences often, but not always, include teams from a common geographic region.
In the United States and Canada, the National Hockey League (NHL) and National Basketball Association (NBA) are divided into the western (NHL, NBA) and eastern (NHL, NBA) conferences, with multiple divisions within each conference (three in each NBA conference, two in each NHL conference). In both leagues, a total of sixteen teams (eight from each conference) qualify for the leagues' postseason playoffs. In the NHL, division winners are guaranteed to qualify and are awarded the highest seeds, meaning they will have home-ice advantage in a given round against a non-division-winner. Starting with the 2015–16 season, NBA division winners are not guaranteed to qualify for the playoffs. The playoff spots instead go to the eight top teams in each conference by overall record, with home-court advantage in each playoff series based solely on record. Major League Soccer also divides itself into an Eastern and Western Conference, though it does not have divisions within them; it too allocates an equal number of teams from each conference to play for its MLS Cup Playoffs (since 2015, this has been six teams each).
The National Football League has an American Football Conference (AFC) and a National Football Conference (NFC). Both conferences have 16 teams, and each conference is divided into 4 divisions of 4 teams each. Each of the 4 division winners is guaranteed one of the top 4 seeds in the playoffs. These conferences, for the most part, derive from the fact that they were once separate organizations: the original National Football League and the 1960s American Football League; the two entities merged in 1970, with each league forming the basis of the NFC and AFC respectively.