Question: [The Wikipedia article on Korea](https://en.wikipedia.org/wiki/Korea) states that South Koreans call Korea 한국, while north Koreans call it 조선. Do 'Korea', '한국', and '조선' all refer to the same thing? If so, how did the three different names come about?

Answer: 
'Joseon(조선)' is a country that has been destroyed and does not exist at present. In a modern society divided into South and North Korea(북한), there is only North Korea that calls itself Joseon. The official name of Korea (남한, South Korea) is Republic of Korea.
On the rare occasions on which the ROK and DPRK have cooperated in international sporting events (1991 table tennis world championships, summer olympic opening ceremonies 2000 and 2004 and winter olympics women's ice hockey 2018), they have used the name 'Korea'.

In general, though, Koreans use the name 'Korea' *when they speak in English*. At least South Koreans do - I haven't met any North Koreans.