The primary difference between an ionic bond and a covalent bond lies in how they form. An ionic bond occurs when one atom transfers electrons to another, resulting in charged ions that attract each other due to opposite charges. This typically happens between metals and nonmetals. In contrast, a covalent bond involves the sharing of electron pairs between atoms, often occurring between nonmetals. This sharing allows both atoms to attain stability, resulting in molecules. The type of bond influences the physical and chemical properties of the resulting compounds.