World Champion

A world championship is generally an international sports competition open to elite competitors from across the world, representing their nations, and winning such an event will be considered the highest or near highest achievement in the sport or contest.

The title is usually awarded through a combination of specific contests or, less commonly, ranking systems (e.g. the ICC Test Championship), or a combination of the two (e.g. World Triathlon Championships in Triathlon). This determines a 'world champion', who or which is commonly considered the best nation, team, individual (or other entity) in the world in a particular field, although the vagaries of sport ensure that the competitor recognised at the best in an event is not always the 'world champion' (see Underdog).

Certain sports do not have a world championship. Instead, they may organise a world cup competition, or they may organize both. Often, the use of the term cup or championship in this sense is just a choice of words. Some sports have multiple champions because of multiple organizations such as mixed martial arts, boxing and wrestling.

Certain sports do not have a world championship or a world cup as such, but may have one or several world champions. Professional boxing, for example, has several world champions at different weights, but each one of them is decided by a "title fight", not a tournament.

A certain number of sports hold world championships or world cups which are overshadowed, in terms of prestige, by the same events in the Olympic Games, the most prestigious multi-sports event.

Still other sports may or may not have a true world championship but may designate the winners of a domestic competition to be "world champions." This is especially true of the major professional sports leagues in the United States and Canada; world cups and championships exist in all of the major sports, but the domestic U.S. and Canadian leagues are generally recognized as the world professional championships or the equivalent of a world club championship. (In American football, although an IFAF World Championship exists, the United States is so far above and beyond the other nations it faces that the winner of the U.S.-based Super Bowl, a competition limited to the 32 teams in the National Football League, is commonly recognized as the world champion.)

...
Wikipedia