The Hylia people were the ancient race of humans that the Goddesses had as their chosen people. Their appearance was not unlike that of a common human, except for their pointed ears, so long that their weight made them lay almost perpendicular to the head. According to legend these allowed them to hear messages from the Gods and gave them a form of telepathy. Their eyes too, their gaze, were different than ours, more developed and so were their magic skills.
For a long time, the Hylians flourished in their kingdom, Hyrule, but eventually came a time when they begun to decline. Most forgot the old ways and what the Gods had taught them. This resulted in lust for the legendary relic, the Triforce, but few were aware of where it was hidden anymore, and they knew better than to misuse of it. This lust spread to the other races and eventually led to Hyrule's Civil War and then the Imprisoning War. The Kingdom survived, but after these tragic events, the blood of the Hylia people grew so thin their descendant no longer considered themselves Hylians, the wisdom of the ancient ones, only surviving in their few scrolls they left behind. Also countless artefacts of the Hylia survive, among which some that played a very important role in the history of Hyrule, like the Book of Mudora and the Master Sword. In those last days of war, the Hylian society had taken a feudal form. Still it would seem like they've had a royal family and orders of knights and sages for as long as it can be remembered.
In the world of Termina, while preserving their physical traits, the cultural and political decline of the Hylia (or should we say Ikana?) apparently came to pass much sooner, but so did the first signs of their renaissance which could be witnessed in the commune city of Clock Town. These Hylians call themselves humans just as the round eared people from other lands. They are very skilled in clockworks and hold a traditional yearly celebration, the Carnival of Masks to which they give great importance (as masks seem to have a deep influence on the world of Termina).