Ionic bond -
An ionic bond is the bonding between a non-metal and a metal, that occurs when charged atoms (ions) attract after one loses one or more of its electrons, and gives it to the other molecule, for example sodium and chlorine.
Covalent bond -
A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. The stable balance of attractive and repulsive forces between atoms when they share electrons is known as covalent bonding.
Metallic bond -
Metallic bonding is the electrostatic attraction between the positively charged atomic nuclei of metal atoms and the delocalised electrons in the metal. Figure 1: Positive atomic nuclei (+) surrounded by delocalised electrons.