You booked a trip to Germany, so why does your passport stamp say Deutschland? Your name didn't change from John to Johann, so why should the country's name change? If you've ever wondered why countries go by different names in different languages, you can check out the Endonym map, that displays each country by their own name. Endonyms are a country's name within its own borders (see: United States of America, Detschland, Estados Unidos Mexicanos), while exonyms are what it's known by in other languages (a.k.a. Vereinigte Staaten von Amerika, Germany, Mexico). Many of them are similar-sounding cognates that are easier to say or spell in our native language (Brazil/Brasil or Italy/Italia), or some are descriptive and sometimes derogatory names for a place (see this literal Chinese translated map of Europe, like Italy/Meaning Big Profit).
Can you figure out some of the more difficult English exonyms with a hint?
Elláda: You might recognize this name better from its ancient pronunciation: Hellas, named for a famously beautiful resident.
Hrvatska: Such a combination of consonants might be familiar from one of their famous islands: Hvar.
Miṣr: You'll read this name now in Arabic, not hieroglyphics.
Suomi: The more commonly known name for this country was found on rune stones in nearby Sweden.
Zhōngguó: Our name derives from Persian and Sanskrit, and now also describes a certain kind of porcelain dishes.