Discuss the limitations of value-at-risk and expected shortfall.

    

Discuss, in less than 1200 words, the limitations of Value-at-Risk and Expected shortfall.
Please include appropriate references, with a reference section. 

include:

what is VAR and expected shortfall?

when we use them? How?

what’s the difference between them? 

what’s the benefits and limitations of them?

and research more about them but less than 1200 words in total.