Ionic bond is formed when there is complete transfer of electron from metal to nonmetal. Example: ,
A covalent bond is formed by sharing of electrons between non metals.
A polar covalent bond is defined as the bond which is formed when there is a difference of electronegativities between the atoms. It is also defined as the bond which is formed due to the unequal sharing of electrons between the atoms. Example:
Non-polar covalent bond is defined as the bond which is formed when there is no difference of electronegativities between the atoms or the electronegativities get cancelled due to the geometry of the molecule.
Example:
Hence, HCl is an example of a polar covalent compound.