2. 
The five interlaced rings which are depicted on the Olympic flag
are known as the Olympic rings. These design, featuring rings
coloured blue, yellow, black, green and red interlaced into one
another, is basically the symbol of the Olympic games. The
Olympic rings were designed by Pierre de Coubertin in 1912. The
five rings represented the five parts of the world i.e. the
Americas, Europe, Asia, Africa and Oceania. Both the Americas
were regarded as a single continent, while Antarctica was not
taken into consideration. Though no colour is demarcated to a
particular continent or region, various theories about the
Olympic rings colour meaning tend to associate them with various
citations. For instance, at least one of the five colours among the
Olympic rings is present on the flag of each of the participating
countries. The five Olympic rings were adopted in 1914 and made
their debut at the Belgium Olympics in 1920.

3.  Symbolism of the Olympic Rings
The five interlocking rings represent five continents or major
geographical areas of the world. The five main regions: Africa, the
Americas (North and South America are combined), Asia, Europe and
Oceania.
As it says in the Olympic Charter, the five-ringed symbol "represents the
union of the five continents and the meeting of athletes from throughout
the world at the Olympic Games."
The colours of the rings represent the flags of the countries that
participate in the Olympics. Every flag of a country participating in the
Olympics includes at least one of the following colours: blue, black, red,
yellow, and green.
Baron Pierre de Coubertin conceived the design of both the rings and the
flag. The Olympic Committee adopted the flag in 1914, and it was first
flown at the 1920 Antwerp Games.