3. Freshwater and oceans

Rainwater is the source of fresh water on Earth. It is also considered one of the purest forms of water. As it contains a much smaller proportion of salts compared to oceans and seas; it is called freshwater. A significant part of freshwater is found in the frozen state in the form of glaciers and ice caps. Around \(1\)% of it is found in the liquid state as streams, rivers, lakes, ponds etc. Surface water may also penetrate through porous rocks and gets collected beneath the Earth’s surface. This is called groundwater.

The ocean is a huge body of saltwater that covers about \(71\ \)per cent of Earth's surface. The continents and oceans are unevenly distributed in the northern and the southern hemisphere. The northern hemisphere has more land area compared to that of the southern hemisphere. The northern hemisphere holds \(61\)% of the land, whereas the southern hemisphere holds \(81\)% of water. Due to this pattern of land and water distribution, the northern hemisphere is called the land hemisphere, and the southern hemisphere is called the water hemisphere.

Oceans and seas are regarded as the resource bowl of the Earth because of the immense availability of food, minerals, etc. The present distribution of the world’s oceans and major seas is illustrated on the map.