When you buy a whole life insurance policy, you have to "overpay" for it.
You have to pay for the life insurance part, and you also have to pay into the "savings account" part of the life insurance policy. The insurance and the savings together pay the death benefit out to your beneficiary if you die.
So, for example at age 30, you might have a cash value of $2,000 and $98,000 of life insurance.
At age 40, it might be $20,000 of cash value and $80,000 of life insurance. For dad, at age 65, it's half and half - $50,000 cash value and $50,000 life insurance protection.
If you die, the cash value goes with the pure life insurance part, to pay off the insurance amount.
Dad can "borrow" from the cash value inside the policy, but he has to pay the loan back with interest to the life insurance company, and if he doesn't pay it back, that amount gets subtracted from the death benefit payout from the life insurance policy.
If the term "Cash Value" is used, this will usually mean that amount is guaranteed to be available as "cash" in the policy at that time, assuming there are no loans, and all the premiums have been paid.