Ocean water is the saltwater found in the Earth's oceans, covering about 71% of the planet's surface. It is composed mainly of water (H2O) and contains various dissolved salts, primarily sodium chloride. The average salinity of ocean water is about 3.5%, meaning that every liter of seawater contains approximately 35 grams of salt. The temperature and density of ocean water can vary significantly depending on location and depth. Ocean currents play a crucial role in distributing heat and nutrients, affecting marine life and climate patterns. Additionally, ocean water is essential for marine ecosystems, providing habitat for countless species.