International payments are not sent directly from the sending bank to the receiving bank as a direct A to B transfer. International payments are sent through correspondent banks, which the receiving banks have accounts with in the given currency.
Imagine that you want to transfer money to a friend in the USA. Your friend has a bank account in an American bank, and you have an account in a Danish bank. When you make the international payment, the money does not go directly from your Danish bank account to your friend's American bank account.
Instead, the money goes through several intermediary correspondent banks that act as intermediaries. Your Danish bank sends the money to a correspondent bank, which has a relationship with your friend's American bank. This correspondent bank then transfers the money on to your friend's bank in the USA, which then deposits the money into your friend's account.
So even though it may seem like a simple transfer from A to B, international payments often involve several correspondent banks that facilitate the process and ensure that the money safely reaches the recipient, even across borders.