• Dispersion Forces
  also known as London Forces (named after Fritz London who first described these forces theoretically 1930) or as Weak Intermolecular Forces or as van der Waal's Forces (namd after the person who contributed to our understanding of non-ideal gas behaviour).
• Dipole-dipole interactions
• Hydrogen bonds

• Intermolecular forces (dispersion forces, dipole-dipole interactions and hydrogen bonds) are much weaker than intramolecular forces (covalent bonds, ionic bonds or metallic bonds)
• dispersion forces are the weakest intermolecular force (one hundredth-one thousandth the strength of a covalent bond), hydrogen bonds are the strongest intermolecular force (about one-tenth the strength of a covalent bond).
• dispersion forces < dipole-dipole interactions < hydrogen bonds

from-http://www.ausetute.com.au/intermof.html