What is the kind of bond that forms a salt?
This is an electrostatic bond between cation and anion; in other words an ionic bond.
You have discrete charged particles, i.e. ions, with opposite electric charges. These are electrostratically attracted, and form a strong, non-molecular bond, which operates over the entire ionic lattice. And thus cation and anion, in appropriate quantities, form a
The strength of the interaction here entails high (almost unmeasurable) melting and boiling points, and very poor solubility in non-polar solvents.