what is the difference between accrual based net earnings and cash?

Answer 1

Accrual = income counted when the obligation becomes due (regardless of whether the money is actually received)

Cash = income counted when money is actually received.

Answer 2

Cash based accountig Income statement will be understated if the only cash realised are accounted as earnings where as all the earnings those given on credit are also accounted in Accrual based accounting which tend to be a more truthful way of showing the general state of operations of the company.