Ocean water is the water found in the Earth's oceans, covering about 71% of the planet's surface. It is primarily composed of salt, which gives it a distinct taste and makes it different from freshwater found in rivers and lakes. The average salinity of ocean water is about 3.5%, meaning that there are approximately 35 grams of salt in every liter of seawater. Ocean water plays a crucial role in regulating the Earth's climate and supporting marine life. It absorbs heat from the sun, helping to moderate temperatures around the globe. Additionally, it provides a habitat for countless species, including fish, whales, and coral reefs, making it essential for biodiversity and the health of the planet.