Types of Water
Brackish water is water that has more salinity than fresh water, but not as much as seawater. Usually its because fresh water and salt water have come in contact and mixed together. Usually commonly found where a river meets the sea. Another place where you can find brackish water is in a swamp. There are some seas and lakes that are Bracksish, like the Black Sea and the Caspain Sea.
Naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, icebergs, bogs, ponds, lakes, rivers, and streams. Also underground as grounwater in aquifers and underground streams. Most of the fresh water is from precipitation from the atmosphere. For all the water on the earth only 2.5–2.75% is fresh water.
Salt water is water from the sea, it has a higher saline count then Brackish water. Almost all of the water on earth is salt water. Even though sea water isnt harmful to your body, using it as your main hydration source is not a good idea. Your body will use most of the water to elimiate all the salt you just drank. Unlike humans, Other land and marine animals, such as fish, whales, sea turtles, and seabirds such as penguins, and others can adapt to a high saline habitat.