What is the difference between ionic and covalent bonding?

Ionic bonding is an 'electrostatic' force of attraction between a charged metal and non metal ion or compound. These atoms or compounds become ions due to the loss or gain of electrons. The two ions give or receive electrons and opposites attract, so a negative ion will bond to a positive one.
Covalent bonding arises due to the sharing of electron pairs between two non metal atoms. It is a stronger bond and leaves no free electrons meaning the resulting compound is stronger and doesn't conduct electricity or heat.