How exactly do you explain water? Well, it can mean different things in different situations. In chemistry, water would mean H2O, two part hydrogen and one part oxygen. In biology water would be a polar compound molecule with an uneven pattern of charge in which can mix well with any fluids (I love biology). In a flash flood, water might mean danger. To a thirsty man in the desert, it may mean survival. To a sparklette's administrator water may mean profit. In religion, water may mean purification. To a person taking a shower, water may mean cleanliness. As you can see, water can mean anything, However, in terms of life, water is everything.
Many people take water for granted. We all need water to live. There is no exception. We can live weeks without food, but only 2-3 days without water. To you, a normal person who lives in a community where water is plentiful, water may not seem very important at all.
However, to a thirsty person in a hot Sahara Desert, water would mean the difference between life and death. A person that deprived of water would do any means possible to obtain water, even if it means killing. Valuables such as gold, silver, and diamonds are completely useless, because they do not help anyone and we can survive perfectly fine without them, if not better.
Thanks to the useful properties of water, life is able to carry out its regular functions. Water is a polar molecule, meaning that it has an even pattern of charge. That means that water can mix with almost anything. Cells can carry out chemical reactions within out body with ease. Our world is also perfect for water to exist on, because water can be found in all 3 forms: Gas,