Building cash value is one of the major benefits of a whole life insurance policy.  The company that you have your life insurance policy with will take your cash investment and invest it.  The monies earned from this investment is your return on your investment. 

An advantage to this is the value of your investment is tax-deferred until withdrawn.  As the cash value builds on a whole life insurance policy monies can be borrowed against it.  This allows for flexibility and is one of the benefits of a whole life insurance policy.

But, remember, if you borrow against the cash buildup of the policy, the death benefit amount that will be paid out will be reduced by what you borrowed and any interest added.  

Another feature of whole life insurance, as opposed to term life insurance, is if you ever decide to cancel your policy, or some call it "surrendering", the cash value is available to you.  Of course, how much cash that is available will depend on how long you held the policy and how much was paid in and interest earned.  

In the times we live in, sometimes a policy will need to be cancelled because of financial problems, or a person may decide whole life insurance is no longer needed.  In these cases, the policy is cancelled and the policyholder can get the cash value that has built up.  If you keep the policy, an expiration date will usually occur on your one-hundredth birthday.  An that time the policy is terminated and cashed out.