The modern Olympic Games are the leading international sporting event featuring summer and winter sports competitions in which thousands of athletes across the planet participate in a variety of competitions. The Olympic Games are considered to be the world's foremost sports competition with more than 200 nations participating. The Olympic Games are held every four years, with the Summer and Winter Games alternating by occurring every four years but two years apart. Their creation was inspired by the ancient Olympic Games, which were held in Olympia, Greece, from the 8th century BC to the 4th century AD. Baron Pierre de Coubertin founded the International Olympic Committee in 1894. The IOC is the governing body of the Olympic Movement, with the Olympic Charter defining its structure and authority. The evolution of the Olympic Movement during the 20th and 21st centuries has resulted in several changes to the Olympic Games. Some of these adjustments include the creation of the Winter Olympic Games for ice and winter sports, the Paralympic Games for athletes with a disability, and the Youth Olympic Games for teenage athletes.