What is the difference between cash value and date of death value?

With regard to an annuity, it will completely depend on the structure of the annuity contract and any additional riders that might be attached to that contract.  At a basic level, the death value can be the initial deposit amount, less any withdrawals and market performance.  Most of the bigger companies provide a somewhat enhanced death benefit.  This usually is the initial deposit amount less any withdrawals taken.  They will provide a guaranteed return of initial principal back to the beneficiaries, less any withdrawals taken.  The tricky part here is how the withdrawals are treated.  They can be classified as dollar-for-dollar or pro-rata withdrawals.  Dollar-for-dollar withdrawals are preferred in that they protect the value of the death benefit for the beneficiaries.  An example would be, a person deposits $100k into an annuity and it is worth $70k three years later.  They take a $10k withdrawal.  The dollar-for-dollar withdrawal would reduce the death benefit to $90k.  The pro-rata withdrawal would reduce the death benefit to $85.7k.  The pro-rata is calculated by dividing the withdrawal by the current contract value.  This same percentage is then applied to reduce the death benefit value.  This can be a significant deal if there have been large losses in the contract.  There are also enhanced death benefit riders that can be added for an additional fee.  These can provide a full return of principal to the beneficiaries even after withdrawals and market adjustments have been added to the mix.  This can serve as a fixed-income alternative that has market upside and lifetime income.  Also, there are riders that can simply grow the death benefit by a certain percentage on an annual basis.  This can be used for estate planning purposes for people who might not be insurable.  As for the cash value of an annuity, that is simply the current market value of the annuity less any surrender charges (if applicable).