A review regarding the case where water is considered to be a versatile and adaptive component of the cell that engages in a wide range of biomolecular interactions is discussed. A focus will be given on the distinctions between generic and specific behaviors of biological water to show the "uniqueness" of water to life. Specific topics to be discussed include: water as a liquid and solvent, the aqueous environment of the cell, the nonspecific effects and the specific roles of water in structure and function regarding protein hydration, and lastly, the relation of water and nucleic acids.