Nonpolar covalent bonds and ionic bonds are two extremes of a continuum?

Answer 1

Nonpolar covalent bonds and ionic bonds are two extremes of a continuum from interacting

atoms with similar electronegativities to interacting atoms with very different

electronegativities.

Answer 2

Ionic bonds involve the complete transfer of electrons from one atom to another.
Non-polar covalent bonds involve the equal sharing of electrons by atoms that are boned together.
In between these two extremes we have the polar covalentbond where electrons are unequally shared.

The reason that its called a continuum is that complete transfer is rarely observed- even apparently ionic compounds such as common salt have some covvalent character.