Why scientists care
Chemical bonding describes how atoms are held together through interactions involving electrons and nuclei. Ionic, covalent and metallic models highlight different limiting behaviours rather than three completely isolated worlds.
The useful question is not only “what bond is this?” but “what does this model help predict?”
A concrete example
Table salt is not made of isolated NaCl molecules in the solid; it forms an extended ionic lattice.
Try to notice
Science becomes memorable when a definition is connected to something measurable or observable.