IDN refers to all domain names in non-Latin script. In other words, all domain names in languages with their own script like Arabic, Chinese or Cyrillic. For example, “.中文网” is the Chinese Domain extension “.WEBSITE”.
In order for non-Chinese speakers and computers to be able to read this domain extension, it has to be translated with an IDN converter into the common computer character set called ASCII. The translated version, called puny code, looks like this “.xn--fiq228c5hs”.