Since it is capitalized, the Hongkong Special Administrative Region is a proper name. Therefore, it's called a "region" because that's what the local government calls it. The same thing is true of the "District of Columbia" in the US or the political areas containing the capitals of countries like Mexico, Brazil, and Australia. You have to use whatever the government uses and may not call the location of the city of Washington the Columbia Region, nor may you call Hong Kong the Hongkong Special Administrative District, even if you think Hong Kong should be a "district" and the U.S. capital should be in a "region."What's the difference between the two words? I'm rather confused when to use "distrct" and when to use "region". For example, why is "region" instead of "district" used in Hongkong Special Administrative Region?