Water is essential for life processes due to its polarity and ability to dissolve many substances. The polarity of the water molecule, with oxygen more electronegative than hydrogen, allows it to dissolve both polar and ionic compounds. This polarity also gives water high specific heat and heat of vaporization, enabling it to stabilize temperatures. Water's hydrogen bonding gives it cohesion, surface tension, and the ability to absorb large amounts of heat with only small temperature changes.