* Molecule: Two or more atoms held together by chemical bonds. This is the general definition, and it doesn't care if the atoms are the same or different.

* Compound: A molecule formed from two or more different types of atoms.

So, is a molecule always a compound? No.

* Examples of molecules that are NOT compounds:

* Oxygen (O2): Two oxygen atoms bonded together.

* Nitrogen (N2): Two nitrogen atoms bonded together.

Examples of molecules that ARE compounds:

* Water (H2O): Two hydrogen atoms and one oxygen atom bonded together.

* Carbon dioxide (CO2): One carbon atom and two oxygen atoms bonded together.

In essence:

* All compounds are molecules.

* Not all molecules are compounds.