Deep-sea hydrothermal vents are openings in the ocean floor where heated water rich in minerals is released from beneath the Earth's crust. These vents are typically found along mid-ocean ridges, where tectonic plates are moving apart. The water can reach temperatures of over 400 degrees Celsius and is often dark and acidic, creating a unique environment. These vents support diverse ecosystems, relying on chemosynthesis instead of sunlight for energy. Organisms like tube worms, clams, and bacteria thrive in this extreme environment, forming complex food webs. The study of hydrothermal vents helps scientists understand life in extreme conditions and the Earth's geological processes.