Theory:

Water and its availability
Water is one of the most important substances for the survival of living organisms. One can survive without food, but it is impossible to survive without water.
Have you ever thought that from where do we get our water?
Our planet earth is abundant with water. About two-thirds of the Earth is covered with water. Hence, earth is known as the Water planet or Blue planet.
 
earth-11593_1280.jpg
 
About 97% of the water is found in the form of sea and oceans which have dissolved salts making the water saline.
 
This water cannot be used for drinking, domestic, agricultural, and industrial purposes..
 
Look at the famous lines from the poem “Rime of  the Ancient Mariner” written by S.T. Coleridge in 1798:
 
"Water, water everywhere
Nor any drop to drink"
 
It describes the unfortunate situation of a sailor who lost in the ocean.
 
Water we use in our house is known as freshwater. It is obtained from the ponds, lakes, rivers, and wells.
Sources of water
There are different water sources including, rainwater, seawater, well, ponds, river, and lake.
 
Rainwater:
The form of precipitation that falls on the ground as water drops is known as rainwater.
  
Seawater:
Seawater is the biggest storage of natural water. As it contains the largest amount of dissolved salts and impurities, seawater cannot be used for any other day-to-day functions.
Example:
The red sea, Caspian sea, Caribbean sea, Mediterranean sea, Baltic sea, Arabian sea are some of the examples of seas of the world.
River and lake water:
It mostly comprises of the rainwater, and the form of water collected from a snow of the mountains.
Example:
Ganga, Kaveri, Bhima, Tapti, Yamuna, Narmada, Saraswathi, Godavari, Krishna, Tungabhadra, Sindhu, Pranhita.
Pond:
The area that is filled with water either naturally or artificially and smaller than a lake is known as a pond.
 
pond.png
 
Well:
Water can be found underground; this happens because a portion of the rainwater is absorbed by the ground.
 
bhaktapur-909812_960_720.jpg
Use of water in our daily life
Water is essential for sustaining both plant and animal life. Apart from drinking, there are so many other activities for which we use water.
Example:
It is used for agricultural activities, for domestic purposes, for industrial purposes, etc.