The Gaia hypothesis is a theory that suggests that the Earth is a self-regulating organism. This idea has numerous synonyms, including the Earth as a living system, planetary biophilia, and the theory of earth system science. Other synonyms include the Gaia principle, the living planet theory, and the Earth System Theory. These terms all refer to the same basic concept of the Earth being a complex, interconnected system that maintains its own internal stability and balance. While the idea of the Gaia hypothesis has been debated since its introduction, it remains an important concept in our understanding of the Earth and its environment.