Atom vs Ion
Atom is the smallest neutral unit which can form bonds. And ion is any charged molecule. Ion may be composed of several atoms or a single atom. Atoms are unique and are single type. Ions are two types, positive ions (cations) and negative ions (anions).
The main difference between atom and ion is the charge. Atom is electrically neutral while ion is electrically charged. Always atom contains an equal number of electrons and protons, but in an ion the number of electrons and protons are always different. The maximum number of positive charges that an ion can have is 6. And the maximum number of negative charges is 3. This happens due to two reasons. First one is due to loss of electrons. Hence results positive ions. And the other reason is gain of electrons. Hence results in negative ions. If you take atoms, they always have atomic orbitals, and ions have either atomic orbitals or molecular orbitals or both atomic and molecular orbitals. Atoms can be found only in the in the gaseous phase. But ions can be found in gaseous phase, liquid phase and as well as in solid phase.
Atoms are neutral, ions are charged positively or negatively
Ions are composed of one or more atoms with loss/gain electrons
Cations lack electrons and anions have extra electrons
Atoms are found only in gaseous state.