See how often they participate in the script: HERE.
Character Story: Auru is a well studied Hylian who has spent much of his life traveling and learning about many of the mysteries of his land. When the Twilight Invasion began, Auru returned with interest in helping to fight against the evil. Surprised to find Hyrule's soldiers cowering uselessly, he joined the small resistance group found in Telma's Bar.
Race Story: Humans typically live peacefully with other races throughout all of Hyrule. The more specific Hylian race is a subcategory of humans. They can be differentiated by their ears -- Humans have rounded ears and Hylians have pointed ears.