Fluctlight is a fictional concept from the anime and light novel series Sword Art Online. It refers to a digital representation of a person's consciousness, allowing for the storage and manipulation of memories and emotions in a virtual environment. This technology enables users to experience and interact with their memories in unique ways. In the series, Fluctlight plays a crucial role in exploring themes of identity and the nature of reality. It raises questions about what it means to be human and how memories shape our experiences, making it a significant element in the narrative's exploration of virtual worlds.