Light

Light is a fundamental element present within The Legend of Zelda franchise. Over the course of the years, light has served variable purposes, both storyline-wise and gameplay-wise.

Light as a symbolic element
The most iconic source of light in The Legend of Zelda is the Triforce. In Ocarina of Time, chronologically one of the earliest games in the series, the Sacred Realm is where the aforementioned Golden Relic lies at first, although Ganon is eventually able to get one of the fragments of the Triforce. It's revealed that the Triforce is a gift left by the Golden Goddesses to their land after having created it with their powers. The Triforce is kept in the Sacred Realm in order to avoid the forces of evil to conquer it, and can only be fully earned by those who have a balance of Power, Wisdom and Courage.

In addition to the Triforce, there is also a sage who represents light in Ocarina of Time. This sage is the Sage of Light, and lies in the Sacred Realm itself. Rauru blesses Link with the Light Medallion before he ventures into Hyrule after taking the Master Sword with him. Near the end of the game, Rauru and the Sages create a bridge of light so that Link can make his way to Ganon's Tower and rescue Princess Zelda.

Light is also given homage by a melody, the Prelude of Light, useful for the young hero to warp instantly to the Temple of Time.

Light as a protector seal
In A Link to the Past, it is told that the land of Hyrule is located within the Light World. The reason for this is because, prior to the events of the game, Ganon took power of the Sacred Realm after reaching the whereabouts of the Triforce, and turned said realm into the Dark World; therefore, when a being from the Light World somehow moves to the Dark World, he or she loses any protection against darkness and shapeshifts. Only when the individual exits from Ganon's domains, he or she will recover from its influence upon exposition to light.

In Twilight Princess, light plays a similar role as in A Link to the Past. The land of Hyrule is blessed by four Spirits of Light: Ordona, Faron, Eldin, and Lanayru. With their holy powers, these Spirits protect the different provinces in the land. When the Shadow Beasts led by Zant defeat these Spirits, the influence of twilight is able to cover the land of Hyrule, rendering its inhabitants defenseless and turned into ghosts, creating an atmosphere of despair. Under these circumstances, Link must retrieve the Tears of Light by defeating the Shadow Insects holding them. Light is also capable of keeping far away the forces of darkness, this includes beings like Midna who aren't evil.

It's also revealed that light is actually essential for the inhabitants of the Twilight Realm as well. Because there is no Sun in their world, the Palace of Twilight keeps two sacred artifacts, the Sols, which bring protection to the Twili people. Without these sources of light, they will be turned into monsters.

Light as a bringer of force
It is revealed in The Wind Waker that the Master Sword must be blessed by light in order to show its Power to Repel Evil. Whereas the Sages of Light, Forest, Fire, Water, Shadow and Spirit are tasked to seal evil, the Sages of Earth and Wind must pray inside their respective temples in order to infuse the Master Sword with the aforementioned power. In Twilight Princess, however, the Master Sword is blessed instead by the light from the Sols in the Twilight Realm, and this light is the only one capable of penetrating Zant's defenses. It's unknown whether or not this light has effect in the Light World as well, however.

Light can also be materialized as a weapon in the form of the Light Arrows. These divine arrows are capable of vanquishing darkness more efficiently than any other weapon and, as shown in Ocarina of Time, they also lift evil seals. The Light Arrows are, among with the Silver Arrows, the ultimate weapon to defeat Ganon.

Light as a puzzle device
In Ocarina of Time, light is introduced as a puzzle device, a trait that is carried over the 3D installments. In general, there may be blocks or walls that react to light, and when they do there is a direct effect on a mechanism, usually a door opening; chests may be unveiled this way as well. Depending on the situation, light can be brought to the sensitive objects by either using the Mirror Shield, or simply moving the objects to the source of light. In The Wind Waker, Medli can help Link solve light-based puzzles, as she has a harp capable of reflecting light; also in this game, light is the only element that can remove fog, and can purge Link from any fog that has reached him.

Majora's Mask is currently the only game where Light Arrows are consciously used to solve puzzles. In the Stone Tower Temple, they're useful to invert the position of some rooms, and even flip the entire dungeon. Also exclusive to this game is that the arrows can supersede the Mirror Shield in every aspect, as they too can remove or activate sun blocks or sun marks in the walls. In Twilight Princess both the Sols and the Master Sword when infused with their light are capable of keeping away the fog that infests the Palace of Twilight, and with it some light-sensitive orbs can be activated as well.

In Phantom Hourglass and Spirit Tracks, light puzzles take a new approach. In the former, there are statues that emit a blue laser beam, which usually are intended to pinpoint a spot; the Temple of Courage, for example, can only be opened when three sources of light are redirected towards its locked door. In the latter game, there are crystals that emit laser beams after Link plays the Song of Light with the Spirit Flute (which also unveils any buried crystal).