The Olympic rings do not actually represent countries or continents, but they do represent the five major colors that can be found in world flags, including blue, yellow, black, green and red. It is a common misconception that the rings designate specific continents.
Pierre de Coubertin created the rings, in 1913, to represent the activity of the Olympic movement. The rings are incorrectly said to correspond with North and South America as one area and then Africa, Asia, Australia and Europe. Since there are seven continents in the world, there would have to be seven rings to embody the spirit of the Olympic games.