What water owes to them
Water is a small, light molecule. On size alone it ought to be a gas at room temperature — and it is a liquid, because of the attractions between its molecules.
Were those attractions absent, water would boil away long before reaching the temperature of a warm room, and there would be no rivers, no oceans and no life as we know it.
Three properties that follow
A high boiling point
Separating the molecules takes far more energy than the size of a water molecule would suggest, so water boils at 100 °C rather than at some temperature far below zero.
A high specific heat capacity
A great deal of heat can be absorbed for a small rise in temperature, because much of the energy goes into disturbing the attractions rather than into speeding the molecules up. This is why the sea warms and cools far more slowly than the land beside it.
Water is denser than ice
When water freezes, the attractions hold the molecules in an open, regular arrangement that takes up more room than the liquid does. Ice is therefore less dense than water, and floats on it.
Hydrogen bonds
The intermolecular bonds in water have a name of their own: they are hydrogen bonds. Not every polar molecule forms them. A hydrogen bond requires the positive pole of the molecule to be a hydrogen atom, and the negative pole to be an atom of high electronegativity — fluorine, nitrogen or oxygen.
They are not confined to water. Hydrogen bonds also hold together the biological molecules — proteins, DNA and RNA — and it is largely they that give those molecules their shapes.
Inside and between
Keep the two apart. Covalent bonds act inside a molecule and decide what the substance is; intermolecular bonds act between molecules and decide how the substance behaves — whether it melts, boils, or floats when frozen.