The same temperature is its freezing point. At this temperature both liquid water and solid ice can exist together. It can dissolve rocks by moving over them and bringing the materials to the ocean. Water brings the nutrients into the soil that helps plants grow. Water can even dissolve the food in your stomach.
Some substances require a lot of heat to change.
Others take much less. Water has the highest heat capacity of any substance, except for ammonia. Water is important scientists to study, because it is so important to people.