According to this rule, atoms can combine either by transfer of valence electrons from one atom to another or by sharing their valence electrons in order to attain nearest noble gas configuration by having an octet in their valence shell.
Limitations of octet rule:
1.The rule failed to predict the stability and shape of the molecule.
2.It is based upon the inert values of noble gases.
3.The octet rule is not satisfied for all atoms in a molecule having odd number of electrons.
Inert gas means- Any of the unreactive gaseous elements also known as noble gas.