Cohesion is the intermolecular force that holds molecules together within the same phase. Hydrogen bonding is a particular type of dipole-dipole interaction that occurs between molecules that have a hydrogen atom bonded to a highly electronegative atom, such as oxygen, nitrogen, or fluorine. The hydrogen atom in a hydrogen bond has a partial positive charge, while the electronegative atom has a partial negative charge. These partial charges attract each other, forming a hydrogen bond.

Hydrogen bonds are stronger than van der Waals forces, but weaker than ionic bonds or covalent bonds. They are responsible for the high surface tension of water, the ability of water to form droplets, and the high boiling point of water compared to other liquids of similar molecular weight.