A champion is the victor

Victory

Victory is successful conclusion of a fight or competition..Victory may refer to:**strategic victory**tactical victory** Pyrrhic victory, a victory at heavy cost to the victorious party**Victory columns**Victory Monuments**Victory personified...

 in a challenge, contest

Contest

A contest is an event in which at least two teams or individuals compete. There may be an award to a winner or awards for multiple top performers, but a contest may be imposed for training...

 or competition

Competition

Competition is a contest between individuals, groups, animals, etc. for territory, a niche, or a location of resources. It arises whenever two and only two strive for a goal which cannot be shared. Competition occurs naturally between living organisms which co-exist in the same environment. For...

.

There can be a territorial pyramid of championships, e.g. local, regional / provincial, state, national, continental and world championships, and even further (artificial) divisions at one or more of these levels, as in soccer. Their champions can be accordingly styled, e.g. national champion, world champion.
In certain disciplines, there are specific titles for champions, either descriptive, as the baspehlivan in Turkish oil wrestling, yokozuna in Japanese sumo

Sumo

is a competitive full-contact sport where a wrestler attempts to force another wrestler out of a circular ring or to touch the ground with anything other than the soles of the feet. The sport originated in Japan, the only country where it is practiced professionally...

 wrestling

Wrestling

Wrestling is a form of grappling type techniques such as clinch fighting, throws and takedowns, joint locks, pins and other grappling holds. A wrestling bout is a physical competition, between two competitors or sparring partners, who attempt to gain and maintain a superior position...

; or copied from real life, such as the koenig and kaiser ('king' and 'emperor') in traditional archery

Archery

Archery is the art, practice, or skill of propelling arrows with the use of a bow, from Latin arcus. Archery has historically been used for hunting and combat; in modern times, however, its main use is that of a recreational activity...

 competitions (not just national, also at lower levels) in the Low Countries.

• In a broader sense, nearly any sort of competition can be considered a championship, and the victor of it a champion. Thus, there are championships for many non-sporting competitions such as spelling bee
  Spelling bee
  A spelling bee is a competition where contestants, usually children, are asked to spell English words. The concept is thought to have originated in the United States....
  
  s or wargames
  Wargaming
  A wargame is a strategy game that deals with military operations of various types, real or fictional. Wargaming is the hobby dedicated to the play of such games, which can also be called conflict simulations, or consims for short. When used professionally to study warfare, it is generally known as...
  
  . In this context, it is used as an noun. An example would be, "Bianca is a CHAMPION".

• It is also possible to champion a cause. In an ideological sense, encompassing religion, a champion may be an evangelist, a visionary advocate who clears the field for the triumph of the idea. Or the champion may merely make a strong case for a new corporate division to a resistant board of directors. Such a champion may take on responsibility for publicizing the project and garnering funding. Such a champion is beyond a simple promoter. Here it is used as a verb. An example is, "The fundraiser championed rights for everyone".

• A national champion is a large company that is dominant in its field and favored by the government of the country in which it is based in the belief that it will be in that country's interests if the company is successful in foreign markets. The practice is controversial, and not widely believed by economists to be beneficial, but has long been a policy of France
  France
  The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
  
   and other countries.

The original meaning of the word partakes of both these senses: in the Feudal Era

Feudalism

Feudalism was a set of legal and military customs in medieval Europe that flourished between the 9th and 15th centuries, which, broadly defined, was a system for ordering society around relationships derived from the holding of land in exchange for service or labour.Although derived from the...

, knights were expected to be champions of both prowess in combat and of causes, the latter most commonly being either patriotic, romantic or religious in nature. This reaches its most literal in a trial by combat

Trial by combat

Trial by combat was a method of Germanic law to settle accusations in the absence of witnesses or a confession, in which two parties in dispute fought in single combat; the winner of the fight was proclaimed to be right. In essence, it is a judicially sanctioned duel...

, in which each combatant champions the cause of one side of the trial. A "King's Champion

Queen's Champion

The feudal holder of the Manor of Scrivelsby since 1066 has held that manor from the Crown by grand serjeanty of being The Honourable The King's/Queen's Champion. Such person is also Standard Bearer of England.- Origins :...

" is appointed for ceremonial purposes at the coronation of an English Monarch, to defeat any challenger to the monarch's right to be crowned.

World Champion is a title used to denote a winner of a World championship

World championship

A world championship is the top achievement for any sport or contest. The title is usually awarded by contests, ranking systems, stature, ability, etc. This determines the best nation, team, individual in the world in a particular field. Certain sports do not have a world championship, instead...

in a particular sport, discipline or game.