The attractive force which holds various consti-tuents (atoms, ions, etc.) together in different chemical species is called a chemical bond.

Every system tends to be more stable and bonding is nature's way of lowering the energy of the system to attain stability.

The types of chemical bonding are as under.

$(1)$ Kossel – Lewis approach

$(2)$ The valence shell electron pair repulsion ($VSEPR$) theory

$(3)$ Valence bond theory ($VB$)

$(4)$ Molecular orbital theory ($MO$)