Fairies are a race that have some sort of magical powers and usually aid Link in his quest. Navi is Link's companion in Ocarina of Time, although there are others. They are pretty much friendly with every race that isn't associated with Ganon. Every Kokiri in Kokiri Forest has a fairy as a guardian, who help and guide them.
There are Fairies that can be found in jars and other items that will restore Link's health, and sometimes magic. Great Fairies, which are large and human-like in appearances, are usually hidden in fountains and will grant Link upgrades and even magic.
