What is resonance energy? Write about its value.

(N/A) The energy of the actual structure of the molecule (the resonance hybrid) is lower than that of any of the canonical structures. The difference in energy between the actual structure and the lowest energy resonance structure is called the resonance stabilisation energy or simply the resonance energy.
Value of resonance energy: The more the number of important contributing structures,the more is the resonance energy. Resonance energy $\propto$ $\text{Number of resonance structures}$. This is particularly important when the contributing structures are equivalent in energy.