Wateris a chemical substance that is composed of hydrogen and oxygen (H2O) and is important for all known styles of life. In typical usage, water refers only to its liquid form or state, but the substance also contains a solid state, ice, and a gaseous state, water vapor, or steam. Water covers 71% of the Earth's surface. On Earth, it is found mostly in oceans and other large bodies of water, with 1.6% of water below ground in aquifers and 0.001% within the air as vapor, clouds, and precipitation. Oceans hold 97% of surface water, glaciers, and polar ice caps 2.4%, and other land surface water like rivers, lakes, and ponds 0.6%. Additionally, a moment amount of the Earth's water is contained within natural bodies and made products.

Ocean:

An ocean is a major body of saline water and a principal component of the hydrosphere. Approximately 71% of the layer (an area of some 361 million square kilometers) is roofed by the ocean, a continual body of water that is customarily divided into several principal oceans and smaller seas. Over half of this area is over 3,000 meters (9,800 feet).

Lake:

A lake (from the Latin word locus) may be a terrain feature (or physical feature), a body of liquid on the surface of a world that is localized to the underside of a basin (another type of land-form or terrain feature; that is, it is not global) and moves slowly if it moves at all. On Earth, a body of water is taken into account by a lake when it is inland, not part of the ocean, is larger and deeper than a pond, and is fed by a river.