Verified answer

Same as between international and intranational. Former is between different countries; latter within a country.

Intermolecular forces are between different molecules -- like bonds between water molecules and solutes.

Intramolecular forces are between different components (atoms) of a molecule -- C=C or C-H or whatever

Intermolecular forces are those between molecules. These include London dispersion forces, dipole-dipole forces, and hydrogen bonding forces.

Intramolecular foreces are those within a molecule or substance. These typically mean covalent and ionic bonds.