Answer: hydrogen bonding
Explanation:
Ionic bond is formed by the transfer of electrons between metals and non metals.
Covalent bond is formed by sharing of electrons between two non metals.
Hydrogen bond is the bond formed between hydrogen and an electronegative atom such as fluorine, oxygen and nitrogen.
Water molecules are bonded by strong hydrogen bonding between the hydrogen atom and the electronegative oxygen atom and thus are bonded by cohesive forces of hydrogen bonds.