It is attracted to itself by hydrogen bonds. Hydrogen bonds are weaker than covalent bonds, but collectively these bonds hold water together and give it its cohesiveness. The amount of energy needed to raise the temperature of one gram of water by one Celsius degree is called a Calorie. One Calorie is about twice as much energy as you need to warm one gram of most other fluids by the same amount. This makes water much better for regulating the temperatures of animals and the environment.
Water also has a very high heat of vaporization.
Converting one gram of cold water into ice requires 80 Calories of energy. Converting the same amount of very hot water into steam requires 540. The high amounts of energy required to change water from its liquid state make water tend to stay a fluid. The process of freezing water involves slowing down the activity of the water molecules until they contract and enter into a solid state. Once the ice is cooled down to 4 degrees or less, the hydrogen bonds no longer contract, but they become rigid and open, and the ice becomes less dense.