On the basis of polarity , the covalent bonds can be of two types :-
1 Nonpolar covalent bond
When covalent bond is formed between two similar atoms for example between hydrogen and hydrogen H2, between oxygen oxygen O2, between chlorine chlorine Cl2 , the shared pair of electrons is attracted by both atoms with an equal force so there is not any kind of unequal distribution of electrons and there remains the equal charge inside the molecule and it remains neutral that is forming the nonpolar covalent bond.
2 Polar covalent bond
In case of Hetro-Atomic molecule like hydrogen chloride HCl , the shared pair of electrons between the two atom gets displaced to words more electronegative atom here in the above case the shared pair of electrons will be displaced to words chlorine atomic molecule like hydrogen chloride, the shared pair of electrons between the two atom gets displaced to words more electronegative atom here in the above case the shared pair of electrons will be displaced to words chlorine And it will develop a polarity that is partial separation of charges, Partial positive charge on hydrogen and partial negative Charge on chlorine.
The Unconditional Guru 