The correct answer to this open question is the following.
The two Koreas are two totally different countries although man, many years ago were one territory.
After a story of too much struggle, after World War II, the Soviet Union tried to spread Communism in many parts of the planet: Rumania, Hungary, East Germany, Albania, Czechoslovakia, Poland, Cuba, and of course, North Korea. On the other hand, the United States tried to stop the spread of Communism applying the foreign policy of containment, and that is why the United States supported South Korea during the Korean War. Those were the tumultuous years of the Cold War.
That is why the two Koreas are different. North Korea is ruled by a dictator, it is a Communist country, there are no freedoms for the citizens, and they are very controlled. They do not have the chance to use the internet and cannot have any contact with people from other countries.
On the other hand, South Korea is a democratic country with a neoliberal Capitalist economic structure. People have more liberties and civil rights.