A hydrogen bond is a bond between a hydrogen atom and the most electronegative atoms such as O, N, F.
Intramolecular bonding occurs between atoms IN a molecule (unite some parts of one molecule) (mostly in organic compounds such as alcohol, carbon acids and so on).
Intermolecular bonding occurs between 2 different molecules and can be compared with Van der Waals interaction. The most common example is hydrogen bonds in water (O-H…O). They also occur in alcohol, proteins, aldehyde solutions and so on)