The Gaia Hypothesis, presented by James Lovelock and Lynn Margulis, suggests that Earth’s biosphere is actually one large, self-regulating organism, which they call Gaia—pronounced various ways: GAY-ah and GUY-ah being the most common in English.
Although we may never be able to prove or disprove this hypothesis, or even find enough evidence to make it a theory, thinking about Earth’s biosphere as a single life form that we are but a small part of helps us understand the inter-connectedness of all life.
Some people worship Gaia as a goddess and some are more scientific about the concept. Most consider the concept of Gaia as a sentient life form with inherent rights to be mythical fantasy, unlike corporations, which the US Supreme Court has determined to indeed be life forms—human life forms, worthy of human rights.
As used at this website, Gaia is short for “all life on Earth functioning symbiotically as a whole.” Other names include, Earth’s biosphere, the ecosphere, planet Earth, Nature, the natural world, the environment, the combined interactions of biosphere, hydrosphere, atmosphere, and lithosphere, and so on.