Hydrogen bond form between water molecules because the + and - ends are attracted.
Explanation:
Hydrogen bond forms between water molecules because of the 'electrostatic force of attraction' between a 'hydrogen atom' and another 'electronegative atom' bearing a lone pair of electrons.
Hydrogen bonds can be both intermolecular and intramolecular. Hydrogen bonds are stronger than Vander Waals interaction but weaker than fully covalent or ionic bonds.
The hydrogen bond is referred as an 'electrostatic dipole-dipole interaction' but it also shows few features belonging to covalent bonding.
