Location and Uses
Ocarina of Time
In Ocarina of Time, the Kokiri Boots are Link's standard footwear. He starts the game with them. As an adult, he can equip the Iron and Hover Boots as well, giving him special abilities. He can equip back the Kokiri Boots at any time.
In Majora's Mask, Link wears the same Kokiri Boots and clothes from Ocarina of Time; however, they cannot be replaced or unequipped.