Hydrogen bonding occurs only with very high electronegative elements, N, O, F. It occurs because hydrogen has only 1 energy level and 1 electron to share. If that electron and the shared one happen to be over on the high electronegative side of a polar molecule at the same time you have an exposed positive charged nucleus. That positive charge can now be attracted to the N, O or F of in another molecule. It is stronger than most VanDerWaal's forces at close range. Dipole occur because of electronegativity differences less than 1.67 and greater than about 0.5. Charge separations then occur. If the charge cloud orientations are not symmetric you now have a dipole or a polar molecule. The greater the electronegativity differences the greater the dipole moment. A delta negative end of a polar molecule has an excees of electrons and it can be attracted to a delta positive end of another molecule where there is a deficit of electrons. The molecules must be very close together. This force is stronger than an induced dipole or a London's dispersion force, but probably less than a hydrogen bond attraction.