Salt water is water that contains a certain amount of salts. This means that its conductivity is higher and its taste much saltier when one drinks it. Salt water is not suited to be used as drinking water, because salt drains water from human bodies. When humans drink salt water they risk dehydration. If we want to drink seawater, it needs to be desalinated first. Salt water can be found everywhere on the surface of the earth, in the oceans, in rivers and in saltwater ponds. About 71% of the earth is covered with salt water.
Freshwater is water with a dissolved salt concentration of less than 1%. There are two kinds of freshwater reservoirs: standing bodies of freshwater, such as lakes, ponds and inland wetlands and floating bodies of freshwater, such as streams and rivers. These bodies of water cover only a small part of the earth's surface, and their locations are unrelated to climate. Only about 1% of the earth's surface is covered with freshwater, whereas 41% of all known fish species live in this water. Fresh water zones are usually closely connected to land; therefore they are often threatened by a constant input of organic matter, inorganic nutrients and pollutants.