Salt water is a type of water that contains a significant amount of dissolved salts, primarily sodium chloride. It makes up about 97% of the Earth's water, found mainly in oceans and seas. The salinity of salt water varies, but it typically averages around 35 grams of salt per liter. This high salt content affects the water's density and buoyancy, making it different from fresh water. Salt water plays a crucial role in the Earth's ecosystem. It supports diverse marine life, including fish, coral reefs, and plankton. Additionally, salt water is essential for regulating the planet's climate and weather patterns. It also serves as a resource for human activities, such as fishing and desalination processes to provide fresh water.