There are several different kinds of governing bodies for sports:
International federations - these take care of one sport (or a group of sports, such as skiing). They create a common set of rules and organise international competitions. Promotion of the sport is also a task of an international federation.
National federation - these have the same objectives as an international federation, but then within the scope of one country, or even part of a country.
Multi-sport event organisers - these take care of the organisation of a certain event which contains more than one sport. The most important example is the IOC, organiser of the Olympic Games.
General sports organisations - these take care of sports related topics, usually for a certain group, such as Catholic or Jewish sport, military or university sport.
Professional leagues
The first international federations were formed at the end of the 19th century.
... out with 25.2% under the age of 18, 4.8% from 18 to 24, 27.3% from 25 to 44, 28.7% from 45 to 64, and 13.9% who are 65 years of age or older. The median age is 41 ...