The domain name is being converted to PunyCode (https://en.wikipedia.org/wiki/Punycode). This is a defence developed to prevent spoofing of domain names using indistinguishable characters from other character sets than ASCII. Before this was fixed by browser developers, it was possible to execute an IDN homograph attack (https://en.wikipedia.org/wiki/IDN_homograph_attack) and spoof sites using characters that looked like e.g., google.com/paypal.com when they rendered in your browser address bar, but were actually a completely different domain as far as automated systems were concerned.

Edit: typo.