Every four years, the Summer Olympics are held and every four years the Winter Olympics are held. When the Modern Olympics began in 1896, the games for both summer and winter were held during the same year, but in different locations. However, in 1992, the games would be held in different years. Starting in Lillehammer, Norway for the 1994 Olympics, the Winter Olympics were held without the Summer Games being held in the same year. In 1996, Atlanta held the Summer Olympics.
Now, they go back and forth with the Olympics happening every two years, but different seasons. The reason for the Modern Olympics taking place every four years is due to that happening during the Ancient Olympics. Evidence shows that they held Olympics every four years for hundreds of years.