What is the difference between primary and contingent beneficiary?

You select a primary beneficiary to receive a specified share of your account in the event of your death. A contingent beneficiary is an alternate person who receives the specified share of your account in the event that none of your primary beneficiaries survive you.

If you name several primary beneficiaries, and one dies before you, then that person's share is divided equally among the surviving primary beneficiaries (unless you indicate otherwise). If none of your primary beneficiaries survive you, then the share goes to the contingent beneficiaries specified. See also Legal Heirs for additional information.