Irish fairies are supernatural beings from Irish folklore. They are often referred to as Sidhe (pronounced 'shee') or Shee (pronounced 'shay'). The Sidhe are believed to be the spirits of ancient gods and goddesses, while the Shee are believed to be the spirits of deceased ancestors. Both types of fairies are said to inhabit the Otherworld, a realm that exists alongside our own. They are known for their mischievous behavior and are often associated with luck and fortune.