The term for a large body of saltwater is an ocean. Oceans cover about 71% of the Earth's surface and are vital to the planet's climate, weather patterns, and the vast ecosystems they harbor. There are five major oceans on Earth: the Pacific, Atlantic, Indian, Southern, and Arctic Oceans. Oceans play a critical role in regulating temperatures, absorbing carbon dioxide, and providing habitats for countless marine species. They are also essential for human activities, including transportation, fishing, and recreation, making oceans vital to both nature and human society.