Metallic bonds are basically bonds between 2 or more metals. Something unique about this kind of bond is that it does not form a compound … at all. The electrons simply move around freely around the cations clustered together. This cluster of cations can easily be reshaped and realigned which gives the metals their durability and malleability.
Ionic bonds are formed when a metal and nonmetal are bonded. The metal gives an electron while the nonmetal gains an electron. Both will then be oppositely charged to each other thus causing them to be attracted to each other. This attraction is what holds the compound together.
Covalent Bonds are bonds typically formed by 2 nonmetals. What happens is that they will share valence electrons. They follow the octet rule wherein 8 valence electrons are needed for stability; although hydrogen is an exception since it needs only 2. The 2 elements will share their valence electrons that both of them will have their needed 8 valence electrons.