The Summer and Winter Olympic Games organized by the International Olympic Committee occur every four years. The Summer Olympics, more popularly known as just The Olympics is a much bigger event with 204 countries participating as of 2012. The Winter Olympics is an event on a relatively smaller scale, with about 88 countries participating in 2014. Even though these events occur every four years, the summer and winter events are staggered so that there's an Olympic event every two years — the Summer Olympics are held every leap year (2000, 2004, 2008), and the Winter Olympics are held 2 years after the leap year (2002, 2006, 2010).
The Summer Olympic Games or the Games of the Olympiad is an international multi-sport event, occurring every four years.
The Winter Olympic Games is a major international sporting event that occurs once every four years.