Din is one of the three Goddesses along with Farore and Nayru that created the land of Hyrule and the Triforce. She is the Goddess of Power, which is the part of the Triforce that Ganondorf holds. Din's role in the creation of the world was the carving of the land with her "strong flaming arms".
At the dawn of time, Din, along with Farore and Nayru, descended upon the chaos that was to become the land of Hyrule, each of them creating a different facet of the realm. According to The Legend of Zelda: Ocarina of Time, Din, "with her strong flaming arms" gave the earth its form. Upon departure, they created the Triforce, the essence of their power, and left it under Hylia's protection.
in Ocarina of Time, Din is depicted as a golden figure surrounded by a red aura and is firstly described as such by the Great Deku Tree. She appears once again in the scene described by Princess Zelda upon her first meeting Link.
The Era without a Hero
During The Era without a Hero, Din along with the others gods heard the pleas of the people of Hyrule who were faced by Ganon's onslaught of evil, instructed them to flee to Hyrule's mountaintops in order to escape the apocalypse they were about to unleash upon the land to halt Ganondorf's invasion by sealing him under The Great Sea along with the kingdom of Hyrule.
During the events of The Wind Waker Din is only seen as a red statue which open the path to the Tower of the Gods once given the matching pearl.
During the events of Twilight Princess, the light spirit Lanayru tell the tale of the creation of the kingdom of Hyrule by the three Goddesses and explain how him and the others light spirits were ordered to seal the power that the Dark Interlopers were using against Hyrule. The Goddesses are also said to have banished the said interlopers into the Twilight Realm.
In A Link to the Past Din is only mentioned in the game manual describing the creation of Hyrule and is said to be the "God of Power" before being renamed to a "deity" in the The Legend of Zelda: A Link to the Past & Four Swords version to fit the Ocarina of Time version.